An optical apparatus according to the present invention includes a cylindrical holding barrel, a plurality of moving lens frames which are held in the holding barrel such that the moving lens frames are moved back and forth in an optical axis direction, and a cam cylinder fitted on an outer surface of the holding barrel so as to move the moving lens frames. The cam cylinder slides and rotates on the outer surface of the holding barrel, and includes a first cam cylinder and a second cam cylinder each having a cam section on an inner surface thereof, and one end face of the first cam cylinder and one end face of the second cam cylinder are coupled to each other such that the first and second cam cylinders are rotated together.