To provide an optically variable filter array apparatus capable of selecting a desired wavelength of a desired channel from WDM-light beams of a plurality of channels.

WDM-signal light beams of m channels ranging in wavelength from λ1 to λn from optical fibers 11-1 to 11-m enter a wavelength dispersion element 17. The wavelength dispersion element 17 disperses the incident light beams in different directions according to their wavelengths, then, applies the light beams to a lens 18. In the lens 18, the light beams of respective channels are turned into strip-like parallel light beams and developed over an xy plane according to channel and wavelength. A wavelength selection element 19 has a pixel structure where pixels are arranged in lattice pattern, for bringing a pixel at a position corresponding to to-be-selected channel and wavelength into a reflective state. The light beams reflected from the wavelength selection element 19 pass through the same path to exit from optical fibers 15-1 to 15-m. By changing reflection characteristics of the wavelength selection element 19 on a pixel-by-pixel basis, characteristics of an optical filter can be varied, so that desired wavelength of given WDM light can be selected.