An endoscopic surgical instrument (41) includes an insertion section (42) to be inserted into a body cavity, a grip section (400) provided to be linked with a base end of the insertion section (42), a wiping section (417) that is provided at a tip end of the insertion section (42) and is pivoted to wipe off extraneous matter (418) adhering to an observation surface (54b) provided at a tip end part of a lens (54b), an axial member (500) that is inserted through the insertion section (42) and is connected to the wiping section (417), and an operation section (419) that is provided over a whole circumference of a tip end (400f) of the grip section (400) in a circumferential direction in a longitudinal direction of the grip section (400), is connected to the axial member (500), and operates the wiping section (417) through the axial member (500). A center axis (501a) of operation section (419) is coaxial to a center axis (501b) of an endoscope (51) when the endoscope (51) inserted through the grip section (400) and the insertion section (42).
