An endoscopic operation assisting device includes a first handle member, a second handle member, and an operation switch. The first handle member and the second handle member are openable and closable. The first handle member includes, in an opening and closing surface portion thereof, a groove forming an insertion section holding hole for holding an insertion section of an endoscope. Further, the first handle member includes a step portion on a surface portion thereof contraposed to the opening and closing surface portion, the step portion including a flat surface which is provided at a distal end side disposed toward the direction of a distal end portion of the insertion section and which is lower than a proximal end side. Meanwhile, the second handle member includes, in an opening and closing surface portion thereof, a groove forming the insertion section holding hole. The operation switch is juxtaposed to one side surface of the flat surface included in the first handle member.