A phase difference element capable of reducing reflection of incident light and a manufacturing method for the phase difference element are disclosed. The phase difference element includes a transparent substrate 11, an interface anti-reflection film group 12 and an obliquely vapor deposited film 13. The interface anti-reflection film group is composed by one or more of alternately high and low refractive index films, with the film thicknesses of the respectively films being equal to or less than the wavelength of light in use. The obliquely vapor deposited film is formed by a plurality of layers of a dielectric material. These layers are alternately obliquely vapor deposited from two directions differing by 180° from each other. The refractive index of the interface anti-reflection film group 12 is higher than the refractive index of the transparent substrate 11 and lesser than that of the obliquely vapor deposited film 13 (FIG. 1).