To remove deposit on a protective film 6 of heating resistors 3, main pulse P3r of multi-pulse drive is set to the width narrower than main pulse width P3s at the normal recording time and wider than the main pulse width starting film boiling in a region on the protective film including heating regions of the heating resistors, and the heating resistors 3 are driven, whereby the deposit is peeled in a wide area including the heating region. After bubbles grow in an ink chamber 9, they shrink and disappear as the heating resistors 3 terminate heating. Liquid rapidly flows into the ink chamber 9 accordingly, and the deposit on the protective film can be removed by cavitation at the time.