A controller is configured to receive an output signal outputted from a light reception element. The controller is configured to perform: an existence detection of controlling a light emission element to emit light and detecting whether an ejection target exists at a facing position based on the output signal; and a distance detection of controlling the light emission element to emit light toward a surface of the ejection target and detecting a distance between the surface of the ejection target and a nozzle surface based on the output signal outputted from the light reception element upon receiving light reflected off the surface of the ejection target. An amount of change of the output signal with respect to change of the distance in the distance detection is larger than an amount of change of the output signal with respect to change of the distance in the existence detection.