A diffractive optical element includes a plurality of layered diffraction
gratings which includes two diffraction gratings made of materials having
different dispersive powers. The plurality of diffraction gratings
includes a first diffraction grating having a plurality of grating
portions provided on a first base surface, and a second diffraction
grating having a plurality of grating portions which are provided on a
second base surface. In the second diffraction grating, a height of the
grating portion of the central circular zone from the second base surface
is greater than a height of the grating portion of the peripheral
circular zone from the second base surface.