A device mounting board includes: an insulating resin layer; a wiring layer disposed on one main surface of the insulating resin layer; and a bump electrode connected electrically to the wiring layer and protruding on a side of the insulating resin layer from the wiring layer. A side surface of the bump electrode is curved inwardly toward the center axis of the bump electrode as viewed in a cross section including the center axis of the bump electrode, and the radius of curvature of the side surface changes continuously from a wiring layer end to a head end of the bump electrode.