The industrial location is generally changed in accordance with the transition of the social structure, the improvement of raw materials and the progress of technique. This article aims to prove how the progress of technique has changed the location, taking copper smelting industry as an example. Surveying the development of copper smelting in our country from the feudal age up to the present, the author has come to the following conclusions.(1) The copper smelting by means of the traditional technique at the Edo period was divided into the copper smelting at mines and the copper refining in Osaka. The former came out from the economic and technical reasons, and the latter from the political reason, that is, the feudal government allowed the refineries in Osaka to hold a monopoly of copper production in order to control the trade of copper.(2) After the Meiji Reformation, new techniques were introduced from the West. But, compared with the modernization of mining technique, smelting technique was very late to be modernized. Up to the days of the Sino-Japanese War the old technique had been dominant in smelting. As the control by the feudal government had been removed, copper refining began to leave Osaka and be carried out at refineries at each mine.(3) Pyritic smelting which began at the Kosaka Mine in the thirty-third year of Meiji was an excellent technique. Especially it was a profit for custom smelting that the process made the combined smelting of copper and gold or silver possible. From this time copper smelting became the core of metal smelting. On the basis of Pyritic smelting, a new copper smelting process (Pyritic smelting-converter smelting-electrolitic refining) was settled. And in the twenty-sixth year of Meiji the revised law of mining admitted the construction of smelters independent from mines. Then the monopolistic capitalists who had nearly established their bases advanced into custom smelting, mostly at the smelters belonging to large mines, in the prosperous days from the Russo-Japanese War till the First World War. Minor industrialists as well as the capitalists constructed custom smelters one by one on the coasts of the Seto Inland Sea that were convenient for collecting ores. These smelters were located on an island or at the end of a peninsula to avoid injury from smoke.(4) The world-wide panic and depression which followed the First World War caused minor industrialists to decline and the capitalists to accomplish the monopoly of copper smelting. And the outbreak of the Manchurian Incident brought the munitions boom and the copper smelting industry flourished again. But the technique remained fundamentally unchanged. Only the process of producing sulfic acid from withdrawn sulphurous acid gas made a remarkable progress, so the injury from smoke was greatly removed.(5) After the Second World War came the age of technical reform; the oxygen smelting at Hitachi, the flash smelting at Ashio and the fluidized bed roasting process at Kosaka were invented. Consequently a great deal of sulfic acid and raw material for iron manufacture was produced as by-products, and copper smelting got closely related with other industries. And the injury from smoke was almost removed. After the end of the war, a lot of ores and scraps were imported and used as raw material more than the ores produced in our country. In this way there is no longer a positive reason why copper smelters should be located in such inconvenient places, as mountains, small islands or peninsulas. New smelters are planned in the littoral industrial districts with a good harbour near the market.