The present invention provides an ink jet printing apparatus having a plurality of caps connected to a common negative-pressure supply source, in which an optimum amount of ink can be sucked and discharged from a plurality of print heads corresponding to the respective caps in spite of a variation in channel resistance among the caps. A plurality of individual suction paths connect a common suction pump to each of the plurality of caps. An introduction condition for a negative pressure to be introduced into each of the caps is set according to the channel resistance of the corresponding individual suction path.