Image pickup unit and endoscope

An image pickup unit comprising:

• an observation optical system of a focus switching type including a fixed lens and a movable lens;
• a fixed barrel that holds the fixed lens;
• a movable barrel disposed in the fixed barrel to be capable of advancing and retracting in a direction along a photographing optical axis of the observation optical system, the movable barrel holding the movable lens;
• a front side stopper that is in contact with the movable barrel at two or more points arranged so as to be vertically separate from each other with respect to the photographing optical axis, the front side stopper restricting movement of the movable barrel in an advancing direction along the photographing optical axis, to hold the movable lens in a position for realizing a first focal length of the observation optical system;
• and
• a stopper member positioned and fixed in a state in which the stopper member is abutted against an outer surface of the fixed barrel by surface contact, the stopper member having a pipe shape and the pipe shape having an interior cavity and being in contact with the movable barrel at opposite sides of the pipe shape, the opposite sides being vertically separate from each other with respect to a central axis of the pipe shape, the stopper member restricting movement of the movable barrel in a retracting direction along the photographing optical axis, to thereby hold the movable lens in a position for realizing a second focal length of the observation optical system.