To provide a cooling device for a thermal head which is small and has a high cooling performance.

The cooling device 31 has end parts of a graphite sheet 33 held between a head substrate 21 and a heat sink 32 of the thermal head 19 and between the heat sink 32 and a pressure welding plate 34 respectively. The graphite sheet 33 has a flexibility and a high thermal conductivity in a plane direction. Heat generated at the thermal head 19 is conducted from the head substrate 21 through a lower spread 38 of the heat sink 32 to a plurality of fins 40 from below. Moreover, heat of the thermal head 19 is conducted through the graphite sheet 33 and an upper spread 39 of the heat sink 32 to the fins 40 from above. The heat conducted to the fins 40 is emitted by a blast from fans 35 and 36.