A roughened cured material allows reduction of surface roughness and increase in adhesive strength between a cured object and a metal layer. A roughened cured material is obtained by advancing curing of an epoxy resin material to obtain a preliminary-cured material and conducting roughening treatment on a surface of the preliminary-cured material. The epoxy resin material contains an epoxy resin, a curing agent, and a silica whose mean particle diameter is not smaller than 0.2 μm but not larger than 1.2 μm. When a roughening-treated surface of the roughened cured material is photographed with a scanning electron microscope, in a 5 μm×5 μm sized area of the roughening-treated surface in a photographed image, the number of particles of the silica that are exposed from the roughening-treated surface and whose exposed portions have a maximum length of 0.3 μM or longer in the image is not greater than 15.