Peeling due to interfacial fracture between a tack-free layer 11 and a heat-conductive layer is prevented. In the tack-free layer, an inorganic filler having a median diameter of 0.5 μM or more is contained in a thermoplastic resin having a glass transition temperature of 60° C. or higher to form concaves and convexes on an adhesive surface. Then, the heat-conductive layer being in contact with the adhesive surface is disposed. The adhesion between the tack-free layer and the heat-conductive layer is strengthened by an anchor effect caused by the concaves and convexes of the adhesive surface, without strengthening the adhesion of the surface opposite to the adhesive surface.