A liquid ejection device includes a liquid ejection head and a capping mechanism. The liquid ejection head includes nozzles for ejecting a dispersion liquid having charged solid particles dispersed in a dispersion medium. The capping mechanism covers the nozzles and receiving the liquid. The capping mechanism includes a cap member, a solid/liquid separation chamber, and a waste liquid tank. The cap member is configured to receive the liquid discharged through the nozzles. The solid/liquid separation chamber is configured to store the liquid and to separate the liquid into the solid particles and the dispersion medium. The dispersion medium separated from the solid particles flows into the waste liquid tank. The solid/liquid separation chamber has a pair of electrodes in contact with the liquid stored therein so that voltage is applied to the electrodes to allow the solid particles to precipitate on a surface of one of the electrodes.