A stereolithography machine comprising: a tank provided with a bottom; a modelling plate facing the bottom; a moving unit suited to move the modelling plate according to a direction of movement that is orthogonal to the bottom; a coupling unit between the modelling plate and the moving unit, comprising a first coupling member integral with the moving unit and a second coupling member integral with the modelling plate and movable with respect to the first coupling member according to the direction of movement; tightening means suited to be operated in such a way as to tighten the coupling members against each other according to a tightening direction that is orthogonal to the direction of movement, in order to lock the mutual movement of the coupling members.