Mitsui Kinzoku Company, Limited
5706・Prime Market・Nonferrous Metals
Business
Mitsui Mining & Smelting Co., Ltd. (formerly Mitsui Mining & Smelting) is a non-ferrous metal materials manufacturer originating from the acquisition of the Kamioka Mine in 1874, with 52 subsidiaries and 10 affiliated companies. The business consists of three segments: "Functional Materials," "Metals," and "Other Businesses" (Automotive Parts was discontinued following the transfer of all shares of Mitsui Kinzoku ACT in November 2025). In Functional Materials, the company manufactures and sells Copper Foil (Carrier-attached Ultra-thin Copper Foil / Electrolytic Copper Foil for high-frequency substrates) for semiconductor and AI applications, Functional Powder (Metal Powder for Electronic Materials, etc.), Sputtering Targets (ITO, etc.), and other products, while the Metals segment handles smelting of Zinc, Lead, Gold & Silver, and Resource Recycling. The company has global manufacturing bases in Taiwan, Malaysia, China, India, Southeast Asia, and other regions, supplying materials that support a wide range of industries from advanced semiconductors to a circular society.
Business Model
By applying material technologies cultivated in metal smelting, the company manufactures and sells high-function materials for semiconductors and communication infrastructure to secure high margins. The Metals Segment combines LME price-linked earnings from Zinc and precious metals with stable earnings from processing recycled raw materials. The Functional Materials Segment is structured to improve profit margins through increased sales volume and optimization of sales prices and product mix; in FY2026 (ending March 2026), the Functional Materials segment's ordinary income margin reached approximately 20%. The company continues to create next-generation materials through R&D expenditure of ¥15,051 million.
Company Strengths
Manufactures the carrier-attached ultra-thin copper foil "MicroThin™" and the electrolytic copper foil for high-frequency substrates "VSP™" at multiple sites in Taiwan, Malaysia, China, and Japan. In FY2026 (ending March 2026), the company enhanced its production capacity for electrolytic copper foil for high-frequency substrates, and has already decided on phased additional expansions from FY2026 onward. By capturing demand for AI servers and semiconductor package substrates, Functional Materials segment sales grew 33.4% year on year to ¥328,447 million.
The company operates a proprietary smelting network at home and abroad that combines smelting processes for Zinc, Lead, Copper, Gold & Silver, enabling the recovery of valuable metals from hard-to-process ores and recycled raw materials. It possesses the technology and processing capacity to meet expanding recycling needs amid the shift toward a circular economy, and the Metals Segment recorded ordinary income of ¥75,085 million in FY2026 (ending March 2026).
As of the end of FY2026 (ending March 2026), the equity ratio stood at 59.1% (up 8.7 percentage points year on year), the ratio of interest-bearing debt to cash flow improved to 1.3 years, and the interest coverage ratio improved to 41.2 times. Through dynamic business portfolio management, including the transfer of shares in Mitsui Kinzoku ACT Corporation, and a reduction of borrowings exceeding ¥519 million, the company's financial foundation was substantially strengthened.
ENVALITH's Perspective
Performance Trend
Revenue was ¥758,532 million (+6.5% YoY), operating profit was ¥130,912 million (+75.1% YoY), and net profit attributable to owners of the parent was ¥91,263 million (+41.1% YoY), with all metrics reaching record highs. The operating margin improved significantly from 10.5% to 17.3%. As external factors, rising average prices of Zinc, Indium, Palladium, and Rhodium and favorable inventory factors boosted the Metals Segment, while in Functional Materials, increased sales volume of copper foil for semiconductors and AI servers contributed to results. On the other hand, a loss on sale of shares of affiliated companies of ¥19,074 million (Mitsui Kinzoku ACT, etc.) was recorded as an extraordinary loss, so the growth in net profit at +41.1% fell short of the growth in recurring profit (+78.9%). For FY2027 (ending March 2027), the company forecasts operating profit of ¥91,000 million (down 30.5%), a significant decline in profit, mainly due to the reversal of market price and inventory factors.
Growth Strategy
Value creation centered on Functional Materials, combined with a transformation of the business portfolio backed by a ¥60.0 billion M&A budget
In response to expanding demand for multilayer boards for AI servers and communication infrastructure, the company has already strengthened production capacity for Copper Foil for high-frequency boards. Phased additional expansion has also been decided for FY2026 (ending March 2026) and beyond. An increase in capacity for atomized copper powder for multilayer ceramic capacitors has also been decided, continuing to expand the supply capabilities of the Functional Materials segment.
Construction work has begun on an initial mass-production plant for Solid Electrolyte for All-Solid-State Batteries, which is expected to become a next-generation storage battery. The company plans to develop this into a pillar of business from 2030 onward, with the Business Creation Division leading the initiative. In October 2025, the carrier for next-generation semiconductor chip mounting (HRDP®) was transferred to the Functional Materials Business Division to accelerate commercialization.
As a "bold initiative" under the Mid-Term Management Plan 2025, the buy-side M&A budget for FY2026 (ending March 2026) has been expanded from the original plan of ¥24.0 billion to ¥60.0 billion. The company is strengthening its structure for both deal origination and execution. The policy is to accelerate the allocation of resources to complement existing businesses in Functional Materials and Metals and to invest in new business areas.
The Kyushu Advanced Materials Development Center was established in April 2026 in the Kyushu region, where the manufacturing industry is concentrated and there is strong industry-government-academia collaboration along with diverse technical talent. The center will build a materials development structure in collaboration with business divisions, promoting the creation of advanced materials that will enhance future competitiveness in fields related to AI infrastructure and advanced semiconductors.
As part of strengthening management with an awareness of capital efficiency, the company completed the transfer of all shares of Mitsui Kinzoku ACT Corporation, a manufacturer and seller of Automotive Door Locks (Side Door Latches), on November 4, 2025. A partial sale of cross-shareholdings was also carried out. From FY2026 (ending March 2026), reportable segments will be consolidated into three categories—Functional Materials, Metals, and Other Businesses—to concentrate resources on high-profitability businesses.
Last updated: July 19, 2026