An image forming apparatus includes a recording head in which a plurality of nozzle groups is formed; a waste-liquid discharging mechanism which includes a plurality of suction caps covering the nozzle groups respectively, a suction mechanism the ink through the suction caps, a plurality of first channels communicating with the suction caps respectively, and a second channel communicating commonly with the first ink channel and with the suction mechanism; and an ink flow-rate control mechanism which control a flow rate of the ink flowing in first channels. Since the image forming apparatus has the ink flow-rate control mechanism, it is capable of sucking evenly the ink from the nozzle groups, irrespective of a shape of the suction cap, and a diameter and a length of the first channels.