A clutch mechanism includes a pulley, an armature, an electromagnet, a plate spring and a damper. The armature combines with the pulley in a direction of a rotation axis. The electromagnet generates attracting magnetic force, which attracts the armature in a joining direction. The plate spring generates resilient force, which urges the armature in an opposite direction from the joining direction. The damper includes an impact mitigation part mitigating an impact when the armature collides with the pulley. The pulley, the armature, the damper and the plate spring are arranged in this order in the direction of the rotation axis. The damper includes a contact portion contacting part of the armature in the direction of the rotation axis. The plate spring includes a pressing part pressing the contact portion on the armature during both the joining and unjoining of the armature and the pulley.