Method for producing a 3D object by means of lithography, comprising: a) providing a layer of photosensitive material in a working volume, which material is arranged so as to harden under the influence of radiation, b) creating, using a mask and a radiation source, a projection image at the outlet of the mask, c) projecting the projection image onto a plane of the material layer that is to be illuminated, d) moving the projection image, in the plane to be illuminated, in a first movement direction, and moving the projection image, in the plane to be illuminated, in a second movement direction that is different from the first direction and is not superimposed on the first direction, said two movement directions being contained in the plane to be illuminated, method wherein, in order to move the projection image in the first movement direction: - the mask is moved in accordance with a movement having a component along an oblique axis that forms an angle with the plane to be illuminated, and - said movement of the mask having the component along the oblique axis that forms an angle with the plane to be illuminated is transformed into the movement of the projection image, in the plane to be illuminated, in the first movement direction contained in the plane to be illuminated, by means of a mirror that reflects the projection image from the mask towards the plane to be illuminated. a) providing a layer of photosensitive material in a working volume, which material is arranged so as to harden under the influence of radiation, b) creating, using a mask and a radiation source, a projection image at the outlet of the mask, c) projecting the projection image onto a plane of the material layer that is to be illuminated, d) moving the projection image, in the plane to be illuminated, in a first movement direction, and moving the projection image, in the plane to be illuminated, in a second movement direction that is different from the first direction and is not superimposed on the first direction, said two movement directions being contained in the plane to be illuminated, method wherein, in order to move the projection image in the first movement direction: - the mask is moved in accordance with a movement having a component along an oblique axis that forms an angle with the plane to be illuminated, and - said movement of the mask having the component along the oblique axis that forms an angle with the plane to be illuminated is transformed into the movement of the projection image, in the plane to be illuminated, in the first movement direction contained in the plane to be illuminated, by means of a mirror that reflects the projection image from the mask towards the plane to be illuminated. - the mask is moved in accordance with a movement having a component along an oblique axis that forms an angle with the plane to be illuminated, and - said movement of the mask having the component along the oblique axis that forms an angle with the plane to be illuminated is transformed into the movement of the projection image, in the plane to be illuminated, in the first movement direction contained in the plane to be illuminated, by means of a mirror that reflects the projection image from the mask towards the plane to be illuminated.