An image pickup unit includes an objective lens unit, 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 having a circular fitting hole in which the optical member is fit from a rear, a first light blocking member disposed in a front of the optical member, 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.