A starter comprises a planetary gear reduction mechanism including an internal gear provided with a cylindrical chamber, a rotary disk, and a friction disk for restricting the rotary disk. The rotary disk is prevented from angularly moving with respect to the internal gear through an elastic member. When a larger load is applied to the internal gear which the elastic member cannot absorb, the rotary disk is released from the friction disk to angularly move to absorb such larger load. <IMAGE>
