Provided is an ink jet recording apparatus including a tray detachably mounted on a tray support portion of an ink jet recording apparatus in which the tray includes a main body having a support surface to support a medium, two of a first positioning pin and second positioning pin which protrude toward a mounting surface on an opposite side of a setting surface of the main body and are used at the time of mounting the main body on the tray support portion, and the tray support portion includes two of a first hole portion and second hole portion in which the two positioning pins are inserted respectively, and a placing portion on which the tray is mounted in a state where the two positioning pins are inserted in the two hole portions.