Abstract: A drum-shaped windmill with a cylinder tube 1 mounted coaxially to the rotation axis of the windmill with one of each of the circular end plates 2,3 on both ends of the cylinder tube 1 is described, featuring sails 6,7,8,9 with a curved streamlined profile which swivel to a limited degree near the edge of both end plates 2,3 on floating axes 10,11,12,13 mounted parallel to the rotation axis of the windmill. The arrangement has been effected in such a way that at least four sails 6,7,8,9 having a curved streamlined profile are distributed on the circumference of the windmill at equal circumferential distances and that the sails 6,7,8,9 are swivelable with their noses 18,21 in front on the floating axes 10,11,12,13 in the area between the edge 4,5 of the end plates 2,3 and the cylinder tube 1.