The disclosure discloses a door device including a panel, a pivoting arm module, and a door. The pivoting arm module includes a holder and a panel-pivoting arm. The holder is located in a doorway of the panel and fixed to the panel. The holder has an entrance and an accommodating trough. The panel-pivoting arm is slidably accommodated in the accommodating trough and can present a received status or an ejected status relative to the holder. The door is pivotally connected to the panel-pivoting arm. When the panel-pivoting arm presents the received status, the door abuts against the panel and closes the doorway, and the appearance surface of the door is flush with that of the panel. When the panel-pivoting arm presents the ejected status, the door leaves the panel and can rotate relative to the panel-pivoting arm to open the doorway.