According to one embodiment, a tablet printing apparatus includes: a conveyor; an inkjet head configured to eject ink from a nozzle to a tablet conveyed by the conveyor to perform printing; an ink tank configured to contain the ink to be supplied to the inkjet head; a moving device configured to change the height of the ink tank; and a control unit configured to control the moving device. The control unit controls the moving device to change the height of the ink tank based on a use amount of the ink figured out in advance to maintain a head difference between the height of the liquid level of the ink in the ink tank and the height of a nozzle forming surface, where the nozzle is formed in the inkjet head, at a predetermined value.