Provided is a liquid ejecting device including an ejecting unit configured to eject a liquid onto a medium, a detector configured to emit light toward an object opposing the ejecting unit and receive reflected light generated by reflection of the light thereby detecting information, and a cover portion including a cover that transmits the light and is disposed at a position to cover the detector. The cover portion is configured to move the cover so as to change a portion of the cover that covers the detector while the detector remains covered.