The invention has been made to prevent ink adhesion or an ink discharge failure caused by ink adhesion due to evaporation of volatile components of ink which occurs when the ink receptor of a printhead is exposed to air for a long time. If an inkjet printhead and an ink tank containing ink to be supplied to the printhead are attached to a carriage, the ink supply port of the ink tank is pressed to the ink receptor of the printhead. In this arrangement, the presence/absence of attachment of the ink tank to the carriage is detected. If it is detected that the ink tank is not attached to the carriage, a suction operation for the printhead is performed and controlled to suck out ink from the nozzles of the printhead.