Abstract: The present invention provides an ink jet head comprising a head substrate 1, a heat-generating resistor 3 and a pair of electrodes 4, which are attached on the head substrate 1, and a top plate 6 disposed above the head substrate 1, the ink jet head being capable of ejecting ink, with which the space between the head substrate 1 and the top plate 6 is filled, through an ink ejection opening by means of heat of the heat-generating resistor, wherein the heat-generating resistor is made of a silicon oxide material selected from the group consisting of (1) a material consisting of TaxSiOy (1.30≦x≦1.70 and 1.20≦y≦1.95), (2) a material consisting of NbxSiOy (1.4≦x≦1.9 and 1.4≦y≦1.9), (3) a TiC—SiO2 resistive material, a TiC content in the resistive material being set within a range from 55 to 90 mol %, and (4) a Ta—Ni—SiOx (1.2≦x≦2.

Abstract: A thermal head comprising a resistance heating element and electrodes for feeding electric power to the resistance heating element formed on an insulating substrate, and a protective layer of filler-containing-glass formed so as to cover the resistance heating element and electrodes, wherein the specific gravity of the glass for forming the protective layer is equal to or higher than the specific gravity of the filler. In this manner, while maintaining the smoothness and enhancing the ear resistance of the protective layer surface, the thermal expansion coefficient of the protective layer is decrease to reduce the thermal stress due to pulse heat generation from the resistance heating element, and moreover the thermal conductivity of the protective layer is enhanced, so that a favorable recorded image is obtained for a long period.