PURPOSE: To provide an optical writing/reading device excellent in reliability excluding printing deficiency or reading deficiency caused by that foreign matter receives the effect of external force to get on the light emitting or detecting part of a chip even when the foreign matter is present in the predetermined space on the inner surface side of a substrate loaded with an optical element chip when a cover member is fitted to the surface of the substrate.

CONSTITUTION: In an LED printing head 1 equipped with a substrate 4 having a light emitting element chip 2 arranged thereon, a cover member 5 covering the surface of the substrate 4 so as to provide a predetermined space S and the light permeable member 6 incorporated in the cover member 5 so as to form the light transmission route C to the light emitting element chip 2, self-adhesive layers 5z, 6z are formed on the inner surface 5x of the cover member 5 forming the predetermined space S and/or the inner surface 6x of the light permeable member 6 by spraying a transparent self-adhesive. The above mentioned same constitution is also adapted to an image sensor.