An IC-mounted card substrate comprising a first sheet member having at least a first support, a second sheet member having at least a second support and an electronic part fixing layer having therein an IC-module and provided between the first sheet member and the second sheet member, wherein the second sheet member has a cushion layer comprising an actinic ray-cured resin on the second support, and a displacement value of needle penetration of the cushion layer obtained by a thermo-mechanical analysis (TMA) apparatus is not more than 30% at temperature of 100° C. and not less than 30% at a temperature of 150° C. based on the thickness of the cushion layer.