A liquid sensor (802) composed of a piezoelectric device is provided on an ink cartridge (800). An actual consumption detection processing section (816) of a recording apparatus control section (810) detects an actual consuming state by detecting an oscillating state corresponding to an ink consuming state using a piezoelectric device. An estimate consumption calculation processing section (814) finds an estimate consuming state by calculating an ink consuming state based on printing amount when printing using ink. For example, a consuming volume is calculated by adding up and multiplying thenumber of printing dots. An estimate consumption calculation processing for finding a consuming volume in detail and an actual consumption detection processing capable of detecting precisely are usedin combination. Preferably, the passage of liquid level is detected as detection of an actual consumption. Consuming volumes prior to and after it are estimated by adding up and multiplying the number of dots.