Provided is a thermal head (1) including: a substrate body (12) constituted through bonding a flat supporting substrate (13) and a flat upper substrate (11), which are made of a glass material onto each other in a stacked state; a heating resistor (14) formed on a surface of the upper substrate (11); and a protective film (18) that partially covers the surface of the upper substrate (11) including the heating resistor (14) and protects the heating resistor (14), in which a heat-insulating concave portion (32) and thickness-measuring concave portions (34), which are open to a bonding surface between the supporting substrate and the upper substrate (11) and form cavities are provided in the supporting substrate (13), the heat-insulating concave portion (32) is formed at a position opposed to the heating resistor (14), and the thickness-measuring concave portions (34) is formed in a region that is prevented from being covered with the protective film (18). Thus, the thickness of the upper substrate is easily measured without decomposing the thermal head.