An insertion part inserted into an insertion hole of a front case in an insertion direction which is a direction of an optical axis and a regulation part for regulating the insertion are formed in a lens holder for holding an image pickup lens. Projections of an engaging part are formed surrounding the insertion part, and projections of another engaging part are formed surrounding the insertion hole. An interval of the projections of the engaging part is wider than that of the projections of the other engaging part, and an interval of the projections of the other engaging part is formed wider than that of the projections of the engaging part. Accordingly, the position of the lens holder relative to the front case is adjusted in a state where the engaging parts and are engaged.