A radiotherapeutic device (1) comprises a guide (9) for moving a radiationgenerator (4) along a path of predetermined radius so that the X-rays (R1)emitted by the radiation generator (4) may cross an isocenter (13), and asupport member (12) for rotating the guide (9) around the axis of an inclinedshaft (11) extending through the isocenter (13). The radiation generator (4)is moved along a spherical surface by the guide (9) and support member (12) toradiate X-rays (R1) toward the isocenter (13) from many directions.
