A medical apparatus includes: an operation portion; an annular wall portion including a base portion connectedly provided to an exterior case and a protruding end portion; an operation lever configured to be tilted by an operator; a cover member including a first fitted portion fitted to the operation lever, a deforming portion configured to deform accompanying a tilt of the operation lever, and a second fitted portion with an inner circumferential surface fitted to an outer circumferential surface of the wall portion; and an elastic member including a contact portion in contact with an outer circumferential surface of the second fitted portion, the contact portion being fixed to the exterior case and being deformed to press the outer circumferential surface of the second fitted portion.