To completely recycle spent types by efficiently forming activated carbon from spent tyres without need for control of temp., or the like, at a low cost, burning an efficiently formed combustible gas at the same time to generate a high-temp. gas to melt metals, and the like, and utilizing the exhaust gas as the drive source and heat source for a gas turbine, a boiler, and the like.

This device is composed of a fumigating chamber 1 provided with a storage part 2 for spent tyres 3, a line for circulating a combustible gas 7 generated from the ignited spent tyres 3, a drive source 13 for circulating the combustible gas 7 in a close state, a means for igniting the spent tyres 3, a means 19 communicating with the fumigating chamber 1 and forcedly sucking the combustible gas outside the chamber, and a melting furnace 18 communicating with and connected to the forced suction means.