The rotation fixing mechanism (30) of the endoscope apparatus (1) includes a rotation portion (32) connected to a rotation unit (14) rotatably disposed, and a rotation portion (32) A fixed portion (34) rotatably supported, an elastic member (33) interposed between the rotating portion (32) and the fixed portion (34), and a rotating portion (32) on the fixed portion (34) side And pressing the elastic member (33) along the rotational axis X direction to generate a predetermined frictional force to fix the rotational position of the rotational unit (14). And.内視鏡装置(1)の回動固定機構(30)は、回動自在に配設される回動ユニット(14)と接続される回動部(32)と、回動部(32)を回動支持する固定部(34)と、回動部(32)と固定部(34)の間に介装された弾性部材(33)と、固定部(34)側に回動部(32)を押圧して、回動軸X方向に沿って弾性部材(33)を圧縮することで所定の摩擦力を発生させて、回動ユニット(14)の回動位置を固定する押さえ部材(31)と、を具備する。