PURPOSE: To forcedly radiate the heat generated in a printing head in order to increase the speed of a dot impact printer and to improve the processing speed of the printer.

CONSTITUTION: In the printing head of a dot impact printer, the vicinity of a coil 1d and the vicinity of the outer peripheral part of the printing head are connected by an L-shape heat exchange element 13 and one end of the heat exchange element 13 is positioned at the center point of the coil 1d arranged in a circular shape and the other end part thereof is connected to the heat sink 12 constituted in the outer peripheral part of the printing head. The end part on the side of the coil of the heat exchange element 13 also contains the coil 1d and is filled with a heat conductive resin 14. The heat exchange element 13 is constituted by sealing a heat conductive pipe 13a with helium 13b and helium is evaporated by the heat generation of the coil 1d and heat is radiated through the heat sink 12.