An endoscope apparatus includes: an endoscope connector； a first optical connector extended from a plug section； first insertion openings of a receptacle section into which the first optical connector is inserted； second insertion openings of the receptacle section into which a second optical connector is inserted； a wrong insertion preventing member that is partially located in the second insertion openings, and is moved, in conjunction with insertion of the first optical connector into the first insertion openings, to a retracted position at which the second optical connector is insertable into the second insertion openings； and a contact member that comes into contact with the wrong insertion preventing member when the first optical connector is inserted into the second insertion openings.
