PURPOSE: To enable temperature abnormality of a coil to be certainly detected, by establishing a heat sink which has at least not less than two tap holes in an array direction of electromagnetic single printing mechanisms, and a temperature detection device engaged with said tap hole.

CONSTITUTION: Single printing mechanisms of an electromagnetic printing head are arranged in a straight line. Then, a heat sink 10 has a plurality of tap holes 14 along an array direction of the electromagnetic single printing mechanisms. Though a temperature detection device 12 is fixed onto the heat sink with a screw 13 by selecting the tap hole 14 on the heat sink 10, the temperature detection device 10 can be freely moved ether to a central part or to a left end of the electromagnetic printing head. Therefore, a position of the temperature detection device can be established by observing a service state. When a service frequency on a left side of the printing head is high, the temperature detection device can be mounted close to said part. Therefore, temperature abnormality of a coil can be certainly detected, and the electromagnetic printing head of high reliability can be obtained.