Disclosed herein is an infrared reflective substrate that can be easily produced by application onto the surface of a base material, has a film having a small film thickness, and achieves both high light permeability and excellent infrared reflective performance. The infrared reflective substrate includes: a transparent base material; and an infrared reflective layer formed by applying a coating agent containing a complex of poly(3,4-disubstituted thiophene) and a polyanion onto the transparent base material, and has a total light transmittance of 60% or higher. The complex preferably has a conductivity of 0.15 (S/cm) or higher, and the infrared reflective layer preferably has a film thickness of 0.50 μm or less.