To provide a belt conveyor furnished with a function to release and apply tension by a snap roller, by simplifying a supporting structure of the snap roller to apply tensile force on a belt without using a tool.

A driving roller 7 is horizontally installed on one end part of a conveyor main body (a), a turn-around roller 2 is horizontally installed on the other end part of the conveyor main body (a), the belt 3 is suspended around an outer periphery of the driving roller 7, the snap roller 8 is supported in parallel by horizontally installing a support shaft 9 on one side of the return passage side of the outer periphery of the driving roller 7, the support shaft 9 and the snap roller 8 are held in a form in parallel, a torsion spring is twisted by revolving a revolving arm 13. It is made possible to transmit motive power by pressurizing the snap roller 8 on the belt 3 on the outer periphery of the driving roller 7 by its twisting reaction and making the belt 3 contact with an outer peripheral surface of the driving roller 7 with pressure.