To make facilities itself comparatively compact without necessitating strong tensile force of a conveyor belt by providing a second driving device for driving the conveyor belt in an inclined part.

Flanges 5, 5 are provided at a fixed interval from both ends of a conveyor belt 1. Flat parts 6, 6 of the conveyor belts on the right and left are mainly used for a second drive. That is, a drive pulley 11 and a driven pulley 12 are arranged on rear sides of the flat parts 6, 6 on the right and left of the conveyor belt 1, an endless belt 13 is stretched around both pulleys 11, 12, and driven pulleys 14, 15 and an endless belt 16 are stretched in a pair on front sides of the flat parts 6, 6 in opposition to it. The flat parts 6, 6 are held in pressure contact with respective endless belts 13, 16, and the drive pulley 11 is driven by a motor and a reducer in this condition. Usually, the reducer and the drive pulley 11 are mutually connected by a shaft coupling.