On the resistor layer between the wiring electrodes, a protective layer formed of silicon oxide, silicon nitride or the like is formed in a thickness of 0.1 to 2.0 ??m, on which a cavitation resistant layer (thickness: 0.1 to 0.6 ??m) is further formed with tantalum or the like to protect the resistor layer 105 from various liquids such as inks.