An image pickup unit of the invention includes an objective lens unit, a rectangular or square cover glass fixed on a light receiving surface of an image pickup device, a circular optical member stuck to a front end face of the cover glass and having a diameter smaller than a diagonal line length of the cover glass, a holding frame fixed to the objective lens unit, and having a circular fitting hole in which the optical member is fit from a rear, a projecting section projecting toward a radial direction inner side in the holding frame, a first light blocking member disposed in a front of the optical member to block visual field external light reflecting on an inner wall surface of the projecting section and traveling to an inside of a pixel formation region of the image pickup device, and a second light blocking member disposed between a rear end face of the optical member and a front end face of the cover glass to block the visual field external light reflecting on a side surface of the optical member and having an angle toward the inside of the pixel formation region.
