To provide a polarized beam splitter which has high reliability and can be made smaller in size at a low cost and to provide a method for manufacturing the polarized beam splitter.

In the polarized beam splitter 10, a polymer birefringent film 2 (anisotropic film) where a grating 3 is formed is adhered with an adhesive on a transparent substrate 1. An overcoat layer 4 formed by filling the grating 3 with an isotropic adhesive 4 also functions as an adhesive to adhere a counter transparent substrate 5. A through groove 7 is formed in the outside of the region where the grating 3 is formed in the polymer birefringent film 2 having the grating 3 formed so as to increase the adhesion strength. The lower and upper transparent substrates 1, 5 are joined with the adhesive filling the through groove 6, which improves the adhesion strength and reliability of the polarized beam splitter.