To obtain a color varying device capable of simplifying the constitution of a projector device by providing an interference type color filter arranged on the reflection surface of a mirror and an inclined state changing means changing the inclined state of the reflection surface of the mirror to a specified direction.

The interference type color filter 35 is formed by successively and alternately laminating two kinds of transparent material having a different refractive index by specified optical thickness on the reflection surface 34A of the mirror 34 in the color varying part 33. By successively inclining the reflection surface 34A of the mirror 34 in a swing direction shown by an arrow (a) based on a driving signal S1 supplied from a driving control part 36, the red light, green light and blue light of white light L10 are orderly and circularly emitted toward a condenser lens 37 in a specified cycle. After the emitted light L11 from the varying part 33 is turned into parallel beams by the lens 37, it is made incident on an LCD 38. Thus, desired wavelength light is easily obtained.