To realize high speed printing while preferably maintaining the resolution and the gloss of a recorded image.

Each heat generating element in a heat generating element array 30 is divided in two, a first heat generating part 40, and a second heat generating part 41 by an electrode 36 for intermediate tapping. In thermal recording of an yellow image or a magenta image, a first driving mode is selected so that transistors Tra1-Tran are switched on or off based on each image data so as to allow conduction of only the first heat generating part 40. In thermal recording of a cyan image in a deep layer, a second driving mode is selected so that transistors Tra1-Tran are switched off as well as transistors Trb1-Trbn are switched on or off based on the image-datum of the cyan image so as to allow conduction of both first heat generating part 40 and second heat generating part 41 simultaneously. They functions as one heat generating part longitudinal in the sub scanning direction.