A protective device for a processing machine is provided. The protective device includes one end portion including an opening portion, another end portion configured to be detachably attached to a tip end tool holding portion of processing machine, a main body portion extending in a predetermined direction from the other end portion to the one end portion and including a hollow portion communicating with the opening portion, and a spherical member rollably supported by the one end portion and protruding in the predetermined direction from an end surface of the one end portion.