The invention relates to an item of furniture and a device for detachably mounting a furniture part on a guide unit, by means of which the furniture part is accommodated on a furniture body so as to be displaceable, and the guide unit includes a body rail that is associated with the furniture body and a movement rail that is associated with the furniture part. A mounting mechanism is present and includes an attachment part, which is mountable on the guide unit and is adjustable from a pre-assembly state mounted on the guide unit into a final assembly state, in which the furniture part is mountable on the guide unit in the intended manner by means of the mounting means.