A mechanical stopper offers a relative rotation range exceeding 360.degree., scarcely generating abrasion powder and the like and having a simple structure. The stopper apparatus has a rotation axis section in which relative rotation is carried out between two members around one rotation axis, for restricting the rotation angle of one of the members with respect to the other member. The stopper apparatus has a contact piece provided on the member and two support members and are provided standing on the other member with a clearance therebetween. A band-shaped elastic member is layered across between the above-mentioned two support members, and the contact piece contacts the elastic member to stop the rotation of the member.