Endoscope

An endoscope comprising:

• an insertion portion configured to be inserted into an object of examination from a distal end side in a longitudinal axis direction;
• a raising base provided at a distal end part of the insertion portion;
• a wire connected at one end to the raising base to move the raising base through traction and relaxation of the wire;
• a guide tube having the wire inserted in a hollow portion of the guide tube;
• a piston inserted into the guide tube to move forward and backward longitudinally within the hollow portion of the guide tube, an other end of the wire being connected to the piston;
• the piston having an outer circumferential surface provided on a distal end side of the piston, the outer circumferential surface being formed so as to project radially outward further than proximal portions of the piston adjacent to the outer circumferential surface such that a clearance is formed between the outer circumferential surface of the piston and a corresponding inner surface of the hollow portion of the guide tube;
• a water-tight seal provided proximally relative to the outer circumferential surface, the water-tight seal being provided to seal a space between the guide tube and the piston at a longitudinal position proximal to the one or more openings;
• a flow path comprising:
• a first flow path provided longitudinally inside the piston,
• a second flow path in fluid communication with a distal end of the first flow path, the second flow path extending from the distal end side of the first flow path and extending radially relative to a longitudinal axis of the piston, and
• one or more first openings formed at an end of the second flow path, the one or more first openings being arranged such that a fluid for cleaning introduced into the first flow path is directed into the clearance;
• and
• an operation member for moving the piston forward and backward longitudinally relative to the guide tube.