PURPOSE: To provide a roller pump which comparatively simplifies constitution, suits various tubes having different diameters, and reliably prevents the occurrence of a pulsating current to a pump delivery part.

CONSTITUTION: A resilient tube 20 is led in and arranged in parallel to the pump suction part 12 side and the delivery part 14 side of a pump casing 10. The resilient tube led in the pump suction part side is disposed in a manner to be communicated to the resilient tube on the pump delivery part side through the inner peripheral surface of a pump casing wherein a displacement part S1 linearly displaced slightly outside a parallel position, an arcuate part S2 in an arc of circle having a diameter larger than the size of an outermost side between the resilient tubes led-in in parallel and extended throughout an approximate 180° arc, and an eccentric arcuate part S3 the arc of circle of which is externally decentered to the pump delivery part side from the terminal point of an arc of circle are arranged, in the order.