a pump for an inkjet printer applying a negative pressure to an inkjet head nozzle , includes : a tube connected to the inkjet head nozzle and being u - shaped ; a plurality of rollers which contact an inner arch of the tube and having a tapered shape ; and a rotor to which the plurality of rollers are rotatably mounted . when the rotor rotates in a direction , at least one of the plurality of rollers rotate and squeeze the tube . when the rotor stops rotating , the plurality of rollers return to a state in which the plurality of rollers do not squeeze the tube due to a recovering force of the tube . the squeezing of the tube generates the negative pressure in the inkjet head nozzle .