DOOR OPENING AND CLOSING DEVICE

A door opening and closing device (60) includes a slider (130) and a main link mechanism (210). The slider (130) moves along a roof (21) of the vehicle body (20) in a front-rear direction, while supporting a proximal end portion of a back door (40) in such a way as to be rotatable around an axis extending in a width direction. The main link mechanism (210) includes one end and an opposite end rotatably coupled to the vehicle body (20) and the back door (40), respectively. The main link mechanism (210) adjusts a posture of the back door (40), depending on a door opening degree by changing a distance between a coupling point to the vehicle body (20) and a coupling point to the back door (40). The main link mechanism (210) decreases the distance as the door opening degree becomes larger.