Infrared reflective substrate

Can be prepared easily by applying to the substrate surface, while exhibiting high light permeability with a small thickness, and, to provide an infrared reflective substrate shows excellent infrared reflection performance. To the transparent substrate, poly (3,4-disubstituted thiophene) and includes an infrared reflective layer formed by applying a coating agent containing a complex of polyanion, total light transmittance of 60% or more infrared reflective substrate that shows. It said complex is preferable to exhibit 0.15 (S / cm) Conductivity over the infrared reflective layer preferably has a thickness of less than 0.50 .mu.m.