Endoscope

An endoscope comprising:

• an insertion part to be inserted into a subject;
• an operation part provided at a proximal end of the insertion part;
• a distal end part main body that is positioned at a distal end of the insertion part and that communicates with a treatment tool lead-out port;
• an elevating base that is provided on the distal end part main body and that causes a treatment tool led out from the treatment tool lead-out port to elevate, the elevating base being provided to be movable between an elevated position and a fallen position;
• an elevating operation lever that rotates in a first direction to move the elevating base to the elevated position and that rotates in a second direction to move the elevating base to the fallen position;
• a bearing member provided in the operation part;
• a coupling member that couples the elevating operation lever and the bearing member;
• and
• a locking mechanism that is provided between the bearing member and the coupling member and that includes:
• a plurality of protrusions provided on one of the bearing member and the coupling member;
• a plurality of holes provided on the other of the bearing member and the coupling member;
• and
• a rail positioned between the holes adjacent to each other,
• wherein in a case where the protrusion is fitted to the hole, the elevating operation lever is locked at a first position, and in a case where the elevating operation lever is rotated in the first direction or the second direction, the protrusion passes through the rail elastically deformed and moves to the hole at a position different from the first position to lock the elevating operation lever at a second position.