The invention concerns an aligning device for a simulator (105) arranged for firing and mounted on a weapon. The weapon has aiming means arranged to indicate the aiming of the weapon in a target area. The simulator is equipped with at least a first element arranged so as to emit an electromagnetic beam along a simulation axis, and adjusting means arranged so as to control the simulation axis in order to align the simulating axis with the aiming means. The device is characterized in that it has means (201) arranged so as to reflect visible light from the beam, and sighting means for alignment that are arranged so as to display a projection of the reflected light superimposed over an image (206) of the target area in an alignment sight window. The projected light is movable within the alignment sight window by means of adjusting means so as to enable placement of the projection at a point at which the aiming means are aimed.