Abstract: A thermal head which is reduced in restriction in dimension of a substrate to allow reduction in size thereof and wherein the contacting characteristic of the substrate with a platen is improved to assure a high quality of printing. The thermal head has a heat generating resistor element and a driving circuit therefor both formed on a substrate, and a suppporting heat radiating member joined to one face of the substrate on which the resistor element is located. The substrate is ground at least at a portion of the opposite face thereof corresponding to a heat generating portion of the resistor element to make the thickness smaller than the other portion of the substrate. Thermal recording is effected by the ground portion of the substrate. The substrate may be made of a transparent or translucent inexpensive material such as quartz or glass. Various forms of supporting heat radiating plate to be incorporated in the thermal printers are also disclosed.