To reduce the number of part items and lower abrasion of a piston on a clutch connecting and disconnecting device connecting and disconnecting a clutch by means of rotation of a driving mechanism.

This clutch connecting and disconnecting device 1 is provided with a motor 2, a motion converting mechanism 3 converting rotating motion of the motor 2 to linear motion, a load accumulating mechanism 4 accumulating a load when the motion converting mechanism 3 moves linearly in one direction and releasing the accumulated load when the motion converting mechanism 3 moves linearly in the reverse direction, and a hydraulic mechanism 6 generating a hydraulic pressure by the linear motion of the motion converting mechanism and connecting and disconnecting the clutch. The load accumulating mechanism 4 is provided with an assist spring 41 connected with the motion converting mechanism 4, which is extensible and contractible by the linear motion of the motion converting mechanism 4, and a spring cover 44 supporting the assist spring 41 at an end part in the extension and contraction direction.