To provide an image formation element array in which the number of parts is decreased to improve assemblability and warpage or twist is prevented.

The image formation element array 20 is composed of a transparent part 21 and an opaque part 22 integrated as an image formation element part. In the transparent part 21, two lens faces of the entrance face 21a in the light emitting element side and a exit face 21b in the scanning side of a photoreceptor or the like, and a prism face 21c to guide a beam L from the entrance face 21a to the exit side to obtain an erect image in the arrangement direction are formed as integrated into one body. The part where the opaque part 22 is formed corresponds to the part conventionally covered with a light shielding member to prevent rays from entering or exiting through a part except for the lens faces. The image formation element part is formed by adding an opaque member to a roughly molded product 30 made of the transparent member and putting the body into a die having an optical face form of high accuracy and molding it by heating or pressurizing.