The invention provides a transparent composite material comprising a cured product of a three-dimensionally crosslinkable resin composition containing tabular inorganic substance having a number-average particle size of 10 to 300 nm and an aspect ratio of 10 to 300 dispersed therein, which material has a small coefficient of thermal expansion against surrounding temperature changes and can be suitably applicable as substrate for display devices, to thereby overcome disadvantages in substrate for display devices using conventional materials that differences in thermal shrinkage between a substrate and an transparent electrode cause cracks in the transparent electrode, resulting in increasing resistance and causing disconnection, and further can provide a display device with high durability.