A polarization conversion element includes first light transmissive substrates and second light transmissive substrates each of which has a light incident surface and a light exiting surface and which are disposed alternately, polarization separation films, reflection films, and retardation plates. One of each of the polarization separation films and a plasma polymerization film is formed on a first surface of each of the first light transmissive substrate. Each of the reflection films is formed on a second surface of each of the first light transmissive substrate. An adhesive layer is formed on a first surface of each of the second light transmissive substrates. The other of each of the polarization separation films and the plasma polymerization films is formed on a second surface of each of the corresponding second light transmissive substrates.