Display device, thin-film transistor substrate, and method for producing same

The purpose of the present invention is to suppress surface unevenness and ensure solvent resistance in a resin substrate for a display panel. A display device (80a) comprises: a TFT substrate (30) including a heat-resistant, transparent first resin substrate (11) and a plurality of TFTs (5); and an opposing substrate (50) including a heat-resistant, transparent second resin substrate (41). The first resin substrate (11) and the second resin substrate (41) are made of polyimide and have a thickness of 5-20 μm and a birefringence of 0.002-0.1.