PURPOSE: To permit high integration of an integrated circuit and at the same time, increase the life of a second heat generating element by providing a first heat generating element on a substrate for preheating of the second heating element and thereby reducing significantly a heating valve required to be supplied to the second heating element itself.

CONSTITUTION: A first heating element 2 is provided on a substrate 1, and this first heating element 2 is covered with a first insulator 3 except an electrode leading-out part. Next, common electrodes 4 and anode electrode 4 of a predetermined pattern are provided on the first insulator 3 along the longitudinal side of the first heating element 2. Then a second heating element 6 is provided on a part of these electrodes 4, 5 and the first insulator 3 between the electrodes 4, 5, and the second heat generating element 6 is coated with a second insulator 7. This first heat generating element 2 is preheated via a leading wire to reduce a heating value required to be supplied to the second heating element 6 itself. At the same time, a battery supply from an IC circuit to drive the second heat generating element is minimized and the high integration of the IC circuit is realized thus increasing the life of the second heat generating element 6.