A door opening and closing device having a rotational mechanism configured to switch a door between a closed position and an open position relative to a base member. The rotational mechanism has a supporting arm integral with the door; a sector gear portion provided on the arm; a rotating gear disposed on the arm at essentially a center of the arc of the sector gear; a first rack portion on the base member and configured to engage the sector gear; and a second rack portion on the base member. The second rack is essentially parallel to the first rack portion and separated by predetermined distance therefrom, the second rack being configured to engage the rotating gear.