PURPOSE: To easily produce a hologram element.

CONSTITUTION: This element consists of the grating layer of the phase compensating film 12 of a periodic dielectric provided on the principal plane of a lithium niobate substrate 10 and the optical diffraction grating layer of the proton- exchange region 11 furnished on the dielctric-free region. Although the element is produced by the self alignment method to realize a high quenching ratio, the man-hour for the production is drastically reduced.