An endoscope includes: a distal end opening 40 of a treatment instrument insertion channel opened at a side surface of a distal end portion 6 a treatment instrument elevator base 30 that is provided at a position facing the distal end opening 40 in the treatment instrument insertion channel and leads a distal end of a treatment instrument protruding from the distal end opening 40, to a desired position and as the treatment instrument elevator base 30 is raised, a guide wire 50 protruding from the distal end opening 40 is releasably engaged by contacting the treatment instrument elevator base 30, a first wall portion 40b located along the insertion direction S of the distal end opening 40, and an insulating member 35 located at a proximal end side of the insertion direction S of the distal end opening 40.
