A pressure production unit provided in an ink jet printer. The pressure production
unit includes: an air pump unit; a drive source that drives the air pump unit;
a storage unit; a temperature sensing unit; and a control unit. The storage unit
stores a first correlation characteristic indicating correlation between a drive
frequency of the drive source and the air pressure of pressurized air produced
in the air pump unit, and the first ambient temperature indicating an ambient temperature
of the air pump unit when the first correlation characteristic is acquired. The
control unit corrects the first correlation characteristic according to the first
ambient temperature and the second ambient temperature sensed by the temperature
sensing unit, and controls the drive source on the basis of the corrected first
correlation characteristic so that a predetermined air pressure is produced.
