An operation portion of an endoscope includes: an insertion-portion-side housing (12) including an insertion portion 2 having a bending portion a main-unit-side housing (13) and an operation lever (14) for operating a bending portion. The insertion-portion-side housing includes: wires (20a to 20d) for bending the bending portion first engagement members (19a to 19d) capable of moving forward and backward in their longitudinal direction and coil springs (24a to 24d). The main-unit-side housing includes: operation wires (29a to 29d) connected to the operation lever second engagement members (27a to 27d) that are connected to the operation wires and are capable of moving in their longitudinal direction and capable of engaging the first engagement members and coil springs (31a to 31d). When the insertion-portion-side housing and the main-unit-side housing are slid and coupled, the first engagement members and the second engagement member are respectively brought into engagement with each other, to thereby transmit an actuation of the operation lever to the bending portion of the insertion portion. According to the present invention, it is possible to replace an insertion-portion-side housing without aligning with the main-unit-side housing.
