The endoscope 1 includes an operation lever portion 30 provided in the operation portion 3 and having an operation shaft 32 and capable of adjusting the bending angle of the bending portion 7 in conjunction with the tilting motion, A flexible outer cover 33 that is watertightly fixed to the operation part 3 so as to cover the outer periphery of the slide body 37 and the operation shaft 32, and which can be deformed by the variation of the internal pressure of the operation part 3 And a returning member 38 for returning the sliding body 37 to the operating section 3 side when the internal pressure of the operating section 3 is depressed. 内視鏡１は、操作部３に設けられ、操作軸３２を有して傾倒動作に連動させて湾曲部７の湾曲角度を調整可能な操作レバー部３０と、操作軸３２の軸方向に進退自在に配設された摺動体３７と、摺動体３７および操作軸３２の外周を覆うように操作部３に水密固定され、操作部３の内部圧力の変動により変形可能である柔軟な外装カバー３３と、操作部３の内部圧力が除圧されたときに、摺動体３７を操作部３側に復帰させる復帰部材３８と、を備えている。
