An apparatus displays an S_Empty informing screen on a display when a count value N reaches a threshold Nth, reads a liquid amount Vc from an IC chip of a cartridge which is installed, calculates an outflow amount Qc of a liquid flowing out from the cartridge to a tank at a period Δt based on the read liquid amount Vc, and erases the S_Empty informing screen from the display when the calculated outflow amount Qc is equal to or larger than a threshold Qth1.