The video display device 4 attached to the operation unit 3 of the endoscope 1 includes a device main body 5 having an accommodation space 5S, a lid body 10 that closes the accommodation opening 5m, and the lid body 10 with respect to the apparatus main body 5. A hinge shaft 31 to be supported, a main body side shaft holding portion 51 through which the hinge shaft 31 formed outside the accommodating opening 5m is inserted, and a lid side shaft holding portion 11 formed in the lid body 10 through which the hinge shaft 31 is inserted. 12 and the first seal member 32 provided on the outer peripheral side of the hinge shaft 31 to prevent liquid from entering the hinge shaft 31 through the gap between the lid side shaft holding portions 11, 12 and the main body side shaft holding portion 51. A hinge lid 33 provided in one of the lid-side shaft holding portions 11 and 12 and disposed in a stepped hole 15 portion into which the hinge shaft 31 is inserted, and a liquid provided in the stepped hole 15 to the hinge shaft 31 And a second seal member 34 for preventing intrusion of the above. 内視鏡１の操作部３に取り付けられた映像表示装置４は、収容空間５Ｓを有する装置本体５と、収容開口５ｍを閉塞する蓋体１０と、蓋体１０を装置本体５に対して軸支するヒンジ軸３１と、収容開口５ｍより外側に形成されたヒンジ軸３１が挿通される本体側軸保持部５１と、蓋体１０に形成されヒンジ軸３１が挿通される蓋側軸保持部１１、１２と、ヒンジ軸３１より外周側に設けられ、蓋側軸保持部１１、１２と本体側軸保持部５１との隙間からヒンジ軸３１への液体の侵入を防止する第１のシール部材３２と、蓋側軸保持部１１、１２の一方に設けられヒンジ軸３１が挿入される段付き孔１５部内に配置されるヒンジ蓋３３と、段付き孔１５内に設けられヒンジ軸３１への液体の侵入を防止する第２のシール部材３４と、を備える。
