Substrate for mounting semiconductor element

A substrate for mounting a semiconductor element thereon has columnar terminal portions formed by concavities provided on an upper surface of a metal plate made of a copper-based material, and is provided with a roughened silver plating layer having acicular projections, applied, as the outermost plating layer, to top faces of the columnar terminal portions. The roughened silver plating layer has a crystal structure in which the crystal direction occupies a largest proportion among the crystal directions , and . The substrate for mounting a semiconductor element thereon facilitates thin design of semiconductor packages produced by flip-chip mounting, can be manufactured with improved productivity owing to reduction in cost and operation time, achieves remarkably high adhesion to sealing resin while keeping the total thickness of plating layers including the silver plating layer to be thin.