Inorganic polarizing plate and method of producing the same

Disclosed is an inorganic polarizing plate that exhibits improved heat resistance while suppressing an increase in lead time resulting from addition of process steps and an increase in costs. An inorganic polarizing plate 1 includes: a substrate (11) transparent to light having a wavelength within a used band; a plurality of linear reflective film layers (12) arranged on the substrate (11) at pitches smaller than the wavelength of the light within the used band; a plurality of dielectric film layers (13) arranged on the corresponding reflective film layers (12); and a plurality of absorptive film layers (14) arranged on the corresponding dielectric film layers (13). Each of the absorptive film layers (14) includes: a property-oriented layer (15); and a heat-resistance-oriented layer (16) made of the same material as the property-oriented layer (15) and having an extinction coefficient greater than an extinction coefficient of the property-oriented layer (15).