A clutch driving device that supplies an assist force for assisting operations of engagement and disengagement of a clutch, the clutch driving device comprising: a spring (71, 171, 271, 371, 771) that extends helically about an axis and is configured to deform in a circumferential direction when seen in an axial direction to thereby generate an elastic restoring force in the circumferential direction; an output portion (71b, 171b, 271b, 371b, 771b) that is disposed at one end of the spring (71, 171, 271, 371, 771) and is configured to output the elastic restoring force from the spring (71, 171, 271, 371, 771); a movement restricting portion configured to restrict movement of the spring (71, 171, 271, 371, 771) in a radial direction when the spring (71, 171, 271, 371, 771) deforms in the circumferential direction; a rotary body configured to rotate in a disengaging direction in disconnecting the clutch and to rotate in an engaging direction in engaging the clutch, the rotary body having, as a rotation center, a rotating shaft extending at a position different from the axis of the spring (71, 171, 271, 371, 771) and in parallel with the axis; and a transfer portion (72, 172, 272, 372, 472, 572, 672, 772) that is provided to the rotary body to be rotatable together with the rotary body and that is configured to contact the output portion (71b, 171b, 271b, 371b, 771b) to transfer the elastic restoring force to the rotary body, wherein the rotary body is configured to receive, as a torque, a reaction force generated by operations of disengagement and engagement of the clutch, and to receive, as the assist force, the elastic restoring force generated by a deformation of the spring (71, 171, 271, 371, 771) in the circumferential direction through the output portion (71b, 171b, 271b, 371b, 771b) and the transfer portion (72, 172, 272, 372, 472, 572, 672, 772), characterized in that, a contact point between the output portion (71b, 171b, 271b, 371b, 771b) and the transfer portion (72, 172, 272, 372, 472, 572, 672, 772) is at a position different from the rotating shaft of the rotary body and the axis of the spring (71, 171, 271, 371, 771), and when the rotary body rotates in a direction in which the elastic restoring force of the spring (71, 171, 271, 371, 771) decreases, the contact point moves toward the axis at least once when seen in the axial direction of the spring (71, 171, 271, 371, 771). a spring (71, 171, 271, 371, 771) that extends helically about an axis and is configured to deform in a circumferential direction when seen in an axial direction to thereby generate an elastic restoring force in the circumferential direction; an output portion (71b, 171b, 271b, 371b, 771b) that is disposed at one end of the spring (71, 171, 271, 371, 771) and is configured to output the elastic restoring force from the spring (71, 171, 271, 371, 771); a movement restricting portion configured to restrict movement of the spring (71, 171, 271, 371, 771) in a radial direction when the spring (71, 171, 271, 371, 771) deforms in the circumferential direction; a rotary body configured to rotate in a disengaging direction in disconnecting the clutch and to rotate in an engaging direction in engaging the clutch, the rotary body having, as a rotation center, a rotating shaft extending at a position different from the axis of the spring (71, 171, 271, 371, 771) and in parallel with the axis; and a transfer portion (72, 172, 272, 372, 472, 572, 672, 772) that is provided to the rotary body to be rotatable together with the rotary body and that is configured to contact the output portion (71b, 171b, 271b, 371b, 771b) to transfer the elastic restoring force to the rotary body, wherein the rotary body is configured to receive, as a torque, a reaction force generated by operations of disengagement and engagement of the clutch, and to receive, as the assist force, the elastic restoring force generated by a deformation of the spring (71, 171, 271, 371, 771) in the circumferential direction through the output portion (71b, 171b, 271b, 371b, 771b) and the transfer portion (72, 172, 272, 372, 472, 572, 672, 772), characterized in that, a contact point between the output portion (71b, 171b, 271b, 371b, 771b) and the transfer portion (72, 172, 272, 372, 472, 572, 672, 772) is at a position different from the rotating shaft of the rotary body and the axis of the spring (71, 171, 271, 371, 771), and when the rotary body rotates in a direction in which the elastic restoring force of the spring (71, 171, 271, 371, 771) decreases, the contact point moves toward the axis at least once when seen in the axial direction of the spring (71, 171, 271, 371, 771).