A device for making panels with three-dimensional curvature from a sheet material, includes a forming impression (5) defined by a membrane (6) including an elastically stretchable skin (11), preferably in combination with a skeleton formed by a grid pattern of flexurally elastic battens (10) which are mobile in longitudinal translation relative to the skin, and a set of elements for selectively deforming the impression acting on the battens (10) of the membrane to impart thereto an adaptable three-dimensional curvature. The invention is particularly useful for making sails.