To prevent recording liquid discharged to a preliminary discharge area provided on the surface of a conveyor belt from adhering to a supporting area or a recording medium on the supporting area.

A preliminary discharge area 8y is provided on the surface 8a of a conveyor belt 8. The preliminary discharge area 8y includes an ink discharge range 8y1 and a treatment liquid discharge range 8y2. The treatment liquid discharge range 8y2 is located upstream of the ink discharge range 8y1 in the conveying direction. The ink discharge range 8y1 is a range to which ink pertaining to preliminary discharge is discharged, and includes discharge ranges 18K, 18M, 18C and 18Y respectively corresponding to four heads. The treatment liquid discharge range 8y2 is a range to which treatment liquid pertaining to preliminary discharge is discharged, and is constituted similarly to the discharge ranges 18K, 18M, 18C and 18Y of the ink discharge range 8y1. Preliminary discharge is performed between sheets P and, in the preliminary discharge area 8y, the treatment liquid is landed upstream of the landing position of ink in the conveying direction.