PURPOSE: To simplify a manufacturing process and to reduce cost by fixing an optical glass provided with a polarizing film to the central part of a bottomed square cylindrical vessel consisting of optical glass so as to incline 45° and injecting liquid having the same refractive index as the refractive index of the optical glass into the square vessel thereby manufacturing a polarizing prism.

CONSTITUTION: The bottomed square cylindrical vessel 5a is formed by using the optical glass 5. The prescribed polarizing film 2 is formed by a vacuum deposition method on one main plane of an optical glass plate 5b of the same kind as said vessel and the polarizing plate 5b made in such a manner is fixed to the central part of the vessel 5a so as to incline 45°. The material of the optical glass 5 for the vessel 5a and the plate 5b is BK7, 1.516 refractive index. The liquid or resin having the same refractive index as the optical glass 5, for example, methyl benzole liquid having 1.515 refractive index is injected into the vessel 5a and the polarizing prism is thus manufactured.