PURPOSE: To produce plate materials of active metals at a low cost with less stages by performing a series of stages for continuous melting, casting, rolling and coiling of the active metal in one furnace of a vacuum or inert gaseous atmosphere.

CONSTITUTION: The active metal, for example, sponge titanium, stored in a hopper 1 is conducted through a chuter 2 onto a hearth 3, and is melted continuously on the hearth 3 by plasma beam torches 4. The formed melt is conducted to a water-cooled continuous casting mold 5 made of copper, by which the melt is cooled and a slab is formed. This slab is fed continuously to water- cooled rolling rolls 7 made of steel, by which the slab is rolled to a prescribed thickness. Thereafter, the rolled plate material is drawn out through pinch rolls 8, and is coiled continuously with a take-up roll 9. A series of such stages are accomplished in one furnace 6 of a vacuum or inert gaseous atmosphere. Thus the stages are simplified and the good plate materials are obtained at a low cost.