An endoscope 1 of the invention includes: an operation portion 3 an insertion portion 2 a treatment instrument insertion channel 17 through which an elongated treatment instrument 30 is inserted a treatment instrument raising base 21 an observation window 25 arranged closer to the operation portion 3 than the treatment instrument raising base 21 in a longitudinal direction of the insertion portion 2 at the distal end portion 5 of the insertion portion 2 and a restricting surface 31A of a restricting portion 31 configured to contact the treatment instrument 30 which is protruded by being directed by the treatment instrument raising base 21 when the treatment instrument raising base 21 is inclined and to restrict an angle of the treatment instrument protruding outside the distal end portion 5, wherein a line 01 connecting the treatment instrument raising base 21 and the observation window 25 is substantially parallel to a longitudinal axis O in a direction in which the insertion portion 2 is inserted, and the restricting surface 31A is provided so as to be located on a line segment connecting the treatment instrument raising base 21 and the observation window 25 when the observation window 25 is viewed from right in front.
