An electronic part-mounted substrate includes a plate made of metal, an insulating material layer which is formed of a ceramic material on a surface of the plate and which has a surface provided with a heat generating IC thereon, and a thermal conductive member which is provided on a surface of IC. The heat, which is generated by IC, is transmitted via the thermal conductive member to the insulating material layer and the plate, and the heat is dissipated to the outside. The heat generated by the electronic part can be dissipated more efficiently. The substrate is applicable to a liquid-jetting head.