Heating elements are driven to continuously perform a dummy jet when the number of accumulated printed sheets reaches a predetermined number that causes the image quality deficiency. The surface temperature of a recording head is increased to T1° C. to boil ink in the individual channel. A bubble attached to the common liquid chamber side edge of the individual channel is spaced from the wall surface to be expanded to be integrated with other bubbles, and then, is discharged from the common liquid chamber to an ink supply chamber by its floating force. The bubble can be removed reliably.