The invention relates to a goniometer (1) and a method for measuring stresses and characterizing microstructure of particles. The goniometer comprises frame (4), a measurement head (7, 8, 9, 10) movably adapted to the frame (4) by a first linear movement unit (5), second linear movement unit (6) and a tilting movement unit (16), for performing measurement at a measurement point. According to the invention the axis of rotation (12) of the tilting movement unit (16) does not coincide with the measurement point, and the device has means (17) for creating arc-formed movement of the measurement head (7, 8, 9, 10) during the measurement with said movement units (5, 6, 16).