A laminate-type diffractive optical element which is easily producible and which allows high optical performance to be easily achieved, and an optical system using the same, are disclosed. In the diffractive optical element formed by laminating a plurality of diffraction gratings, when the distance between the uppermost portion of one diffraction grating and the lowermost portion of the other diffraction grating in two diffraction gratings adjacent to each other along the incident direction of a light is represented by D (.mu.m), these two diffraction gratings are arranged to satisfy the following relation: 10 .mu.m Um lamin-tipo elemento ótico diffractive que sejam fàcilmente producible e que permita que o desempenho ótico elevado seja conseguido fàcilmente, e um sistema ótico usando o mesmo, são divulgados. No elemento ótico diffractive dado forma laminando um plurality de gratings de diffraction, quando a distância entre a parcela a mais mais alta de um grating de diffraction e a parcela a mais lowermost do outro grating de diffraction em dois gratings de diffraction junto a se ao longo do sentido do incident de uma luz está representada por D (mu.m), estes dois gratings de diffraction são arranjados para satisfer à seguinte relação: mu.m 10