A lead frame includes, as an outermost plating layer, a roughened silver plating layer having acicular projections and covering the entire surface of a lead frame substrate made of a copper-based material. The roughened silver plating layer has a crystal structure in which the crystal direction occupies a largest proportion among the crystal directions , , and . The lead frame can be manufactured with improved productivity owing to reduction in cost and operation time, and achieves remarkably high adhesion to sealing resin while keeping the total thickness of plating layers including the silver plating layer to be thin.