To restrain, at low cost, a load applied onto a motor when a door is opened and closed, and to enhance performance.

In this door opening and closing device, the second composed moment M0+M1+M2 composed of the first composed moment M0+M1 composed of an opening moment M1 acting along an opening direction of a backdoor by the first gas pressure type balancer and a closing moment acting along a closing direction of the backdoor by a dead weight of the backdoor, and a moment M2 by the second gas pressure type balancer is set to zero moment precluded from acting on the backdoor in a prescribed position R where the backdoor is opened by a prescribed angle X from a fully closed position P, set to a closing moment Me smaller than a closing moment Ma of the first composed moment M0+M1 in a position lower than the prescribed position R, and set to an opening moment Mf smaller than a opening moment Mb of the first composed moment M0+M1 in a position higher than the prescribed position R.