An apparatus for producing a hologram mask. The apparatus includes a first object light at least partially transmittable through a first original mask having a light transmitting screening pattern, and a first reference light having a first phase difference between it and the first object light. The first object and reference lights cause interference patterns to be recorded a hologram recording material, as do a second object light at least partially transmittable through a second original mask having a light transmitting screening pattern, and a second reference light having a second phase difference between it and the second object light where the second phase difference is not the same as the first phase difference. The resulting first and second original mask images recorded in the hologram recording material can be simultaneously replayed to produce an exposed pattern approximating an exposed pattern of a non-holographic phase shifting photomask.