Grinder (1) as a power tool has a torque limiter (210). The torque limiter comprised a second bevel gear (211); a spindle (213); a flange (212) to which the rotation of the second bevel gear is transmitted, and a plurality of balls (214) which are disposed between the second bevel gear and the flange. The ball is positioned at a first region and the second bevel gear, the ball and the flange rotate integrally thereby the rotation is transmitted to the flange. On the other hand, in a state that a torque exerted on the spindle exceeding the predetermined threshold, a relative rotation between the second bevel gear and the flange is occurred and the ball moves from the first region to the second region while rolling by means of the relative rotation. Therefore, the transmission of the rotation from the second bevel gear to the flange is regulated, and the torque exerted on the spindle is regulated.