Stereolithography machine comprising: - a tank suited to contain a light sensitive resin and provided with a bottom; - a supporting unit associated with moving means suited to move said supporting unit according to a direction of movement which is orthogonal to said bottom; - a modelling plate provided with a modelling surface which faces said bottom in order to support a three-dimensional object; - a coupling unit suited to connect said modelling plate to said supporting unit, configured to allow said modelling plate to translate with respect to said supporting unit, according to said direction of movement, between a first linear position, in which it is further away from said supporting unit, and a second linear position, in which it is nearer to said supporting unit, and to allow said modelling plate to rotate with respect to said supporting unit, according to at least one rotation axis which is perpendicular to said direction of movement, between a first angular position, in which said modelling surface is orthogonal to said direction of movement, and a second angular position, in which said modelling surface is rotated with respect to said first angular position, said coupling unit comprising a housing and a spherical body revolvingly arranged in said housing so that it can rotate at least according to said rotation axis; - releasable clamping means; characterized in that said clamping means comprise: - a hollow body which defines said housing, said hollow body being deformable, so that it can be pressed around said spherical body; - control means suited to be operated to press said hollow body around said spherical body in such a way as to make said modelling plate and said supporting unit integral with each other in such a way as to prevent said translation and said rotation. - a tank suited to contain a light sensitive resin and provided with a bottom; - a supporting unit associated with moving means suited to move said supporting unit according to a direction of movement which is orthogonal to said bottom; - a modelling plate provided with a modelling surface which faces said bottom in order to support a three-dimensional object; - a coupling unit suited to connect said modelling plate to said supporting unit, configured to allow said modelling plate to translate with respect to said supporting unit, according to said direction of movement, between a first linear position, in which it is further away from said supporting unit, and a second linear position, in which it is nearer to said supporting unit, and to allow said modelling plate to rotate with respect to said supporting unit, according to at least one rotation axis which is perpendicular to said direction of movement, between a first angular position, in which said modelling surface is orthogonal to said direction of movement, and a second angular position, in which said modelling surface is rotated with respect to said first angular position, said coupling unit comprising a housing and a spherical body revolvingly arranged in said housing so that it can rotate at least according to said rotation axis; - releasable clamping means; - a hollow body which defines said housing, said hollow body being deformable, so that it can be pressed around said spherical body; - control means suited to be operated to press said hollow body around said spherical body in such a way as to make said modelling plate and said supporting unit integral with each other in such a way as to prevent said translation and said rotation.