A printer includes a head, an electrode, a moving unit, a voltage application circuit, and a controller. The head has an ejection surface having a nozzle. The head is configured to eject liquid from the nozzle. The moving unit is configured to move at least one of the electrode or the head. The voltage application circuit is configured to apply a certain voltage between the head and the electrode. The controller is configured to: drive the moving unit such that the ejection surface faces the electrode; drive the voltage application circuit to apply the certain voltage between the head and the electrode; compare a level of an output signal input to the controller from the electrode with a particular threshold; and based on the comparison result, determine that liquid is present between the ejection surface and the electrode.