An endoscope 1 includes: a conduit 26 that is provided inside an insertion section 2 and into which a guide wire 300 is inserted in a direction opposite to an insertion direction S of the insertion section 2； a bent conduit 27 that is bent to make the conduit 26 communicate with a pipe sleeve 28 of a treatment instrument insertion port 25 provided in an operation section 3； and a forceps plug 30 that is detachable from the pipe sleeve 28. An opening 35 is deviated from a center of the pipe sleeve 28 toward an outer circumferential side of a bending direction of the bent conduit 27.
