When an optical member which have a plurality of luminous flux converters formed in a line on a surface of an optical substrate is mounted on a support substrate having at least one groove, at least two parts of the side surfaces of the optical member are brought into contact with the groove to perform positioning, and an adhesive agent is filled between at least one part of a portion which opposes the groove on the plane of the optical member and which is not in contact with the groove and the support substrate to cause the optical member and the support substrate to adhere to each other.