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 (Z) 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 (Z), 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 (X) which is perpendicular to said direction of movement (Z), between a first angular position, in which said modelling surface is orthogonal to said direction of movement (Z), 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 (X); - 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 (Z) 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 (Z), 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 (X) which is perpendicular to said direction of movement (Z), between a first angular position, in which said modelling surface is orthogonal to said direction of movement (Z), 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 (X); - 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. <EOS>