Disclosed is a polarization conversion apparatus, the apparatus including a first optical device capable of angle-converting incident unpolarized light to allow a polarization direction to be emitted in mutually different first and second linear polarizations, an FEL (Fly Eye Lens) including first and second MLAs (Micro Lens Arrays) arrayed with first and second micro lenses, where first and second linear polarizations of the first optical device incident on the first micro lenses are divided and condensed on an upper side and a bottom side of the second micro lenses of the second MLA, and a second optical device converting the first and second linear polarizations condensed on the upper side or the bottom side of the second MLA at the FEL to any one polarization of the first and second linear polarizations and emitting the polarization.