Provided is an endoscope comprising an opening and closing mechanism for a communication passage, the opening and closing mechanism eliminating the difference in air pressure between the inside and outside of the endoscope. This endoscope is provided with: a partition wall (9) for separating an inner space and an outer space a cylindrical body (21) connected to the partition wall so as to be capable of being watertight, the cylindrical body (21) having an inner wall surface for forming a communication hole (21g) communicating with the inner space, the cylindrical body (21) having a through-hole (21f) passing from the inner wall surface to the outer periphery of the cylindrical body (21) a valve body (25) affixed to the communication hole while water-tightness is maintained and having a check valve section (23) opening and closing depending on the difference in pressure between the inner space and the outer space a first frame body (26) provided on the outer peripheral side of the cylindrical body and configured to be operable in the axial and circumferential directions of the cylindrical body a second frame body (27) mounted over both the cylindrical body and the first frame body while water-tightness is maintained, the second frame body (27) forming a first space (AR) communicating with the through-hole, the second frame body (27) connecting and disconnecting the first space and the outer space by means of the operation of the first frame body a cam pin (29) provided on the outer peripheral surface of the cylindrical body and a cam groove (26d) provided in the first frame body so as to be slidable relative to the cam pin, the cam groove (26d) being guided by the cam pin and having a start point, an intermediate point, and a termination point.Linvention concerne un endoscope comprenant un mécanisme douverture et de fermeture pour un passage de communication, le mécanisme douverture et de fermeture éliminant la différence de pression dair entre lintérieur et lextérie
