An objective that is a concave lens and an ocular that is a convex lens are arranged in a finder housing with a predetermined space between them. The finder housing is molded of a black plastic material. A diaphragm portion is integrally formed inside an inner peripheral portion of the finder housing and between the objective and the ocular. The diaphragm portion is formed to be as large as a lens portion of the ocular. The diaphragm portion serves to block unwanted reflected light.