A pump apparatus includes: a stationary shaft; a rotation-regulating member having a coil main body wound around the stationary shaft, the rotation-regulating member being permitted to rotate in a direction of loosening the coil main body and the rotation-regulating member being restrained from rotating in a direction of tightening the coil main body; a driven rotatable member that may rotate around the stationary shaft when a driving force of a driving source is transmitted; and a suction pump that has a rotary member driven together with rotation of the driven rotatable member and that performs a suction operation when the rotary member rotates. The suction pump is configured such that the rotation-regulating member rotates in the tightening direction of the coil main body when the driven rotatable member rotates in a direction opposite to a direction in which the driven rotatable member performs the suction operation.