A surface-treated copper foil that is for a printed circuit board and that has a silane coupling agent layer on a surface on which roughened particles have been formed. The average height of the roughened particles on the silane-coupling-agent-layer surface is 0.05 μm or more but less than 0.5 μm, the BET surface area ratio of the of the silane-coupling-agent-layer surface is 1.2 or higher, and the micro-surface coefficient Cms of the silane-coupling-agent-layer surface is 2.0 or higher but less than 8.0.