A chassis has plate supporting pillars, insertion holes with engagement pegs, and an aperture brim connected to a lens holding unit. A photographic element package is attached to a plate. Contact surfaces are formed in the aperture brim so that distances from a center axis of a lens holding unit to the two adjacent contact surfaces of the aperture brim are the same as the distances from adjacent standard surfaces of the photographic element package to the center of the photographic element. Plate springs are provided on the mounting member, so that the photographic element package standard surfaces press against the contact surfaces. Plate springs press the plate against the plate supporting pillars. Insertion plates with engagement holes are provided on the mounting member, so that the insertion plates are inserted into the insertion holes and the engagement pegs engage the engagement holes, thereby completing the mounting of the plate on the chassis.