Although production has temporarily stagnated immediately after the end of the war, Japan's industrial revival and its valuable presence in resource-rich countries will revive again, and production will gradually increase.
However, in the Showa 30's, mine development in foreign countries, especially in developing countries, will be over, and global overproduction will occur, and the price of copper will decline. Therefore, a production method has been adopted that pursues the so-called scale merit that increases production while suppressing costs.
Eventually, due to wartime overruns and other mining efforts, the number of powerful veins diminished and mines entering the old world will gradually shift to reduced production. The old smelter was abolished in 1966. In 1972, it separated from its parent company and became Oyorizawa Mine Co., Ltd. and its employees were reduced to 371 employees.
In May 1977 (1978), the long-lasting stagnation of copper prices and the exhaustion of resources led to a long history of mine over 400 years and finally closed.