A birefringent film of the present invention comprises at least one kind of polycyclic compound including a —COOM group (the M denotes a counter ion), wherein an index ellipsoid satisfies a relation of nz>nx=ny. The polycyclic compound includes, for example, acenaphtho[1,2-b]quinoxaline derivative represented by the following general formula (I). The birefringent film of the present invention can be formed thin-type and have a high birefringent index in the thickness direction, since the birefringent film comprises the polycyclic compound.