To provide a belt conveyor with a belt set by snap rollers, having tension releasing or tightening function by using the snap rollers having simpli fied supporting construction, instead of tools.

A driving roller 7 is supported on the homeward side of a conveyor body A, the belt 3 is applied at its homeward side around the outer periphery on the lower face side of the driving roller 7, and supporting shafts 9 are laid and supported on one side and on the other side of the outer periphery of the driving roller 7. The snap rollers 8a, 8b are supported on the supports 31, turning arms 13 are pivotally supported at their base ends on the ends of the supporting shafts 9, torsion springs 12 are fitted at the ends of the supporting shafts 9, and each of the springs 12 is locked at one end to a member on the side of the supporting shaft 9 and locked at the other end to a member on the side of the turning arm 13. By the turn of the turning arm 13, the torsion spring 12 is twisted whose resilient reaction thrusts both rollers 8a, 8b against the belt 3 on the outer periphery of the driving roller 7. The belt 3 is put in pressure contact with the outer periphery face of the driving roller 7 to permit the transmission of power.