The invention relates to a device (1) for guiding a conveyor belt, comprising a guide unit (2) having an outer and an inner hollow cylindrical body (3, 4), the inner hollow cylindrical body (4) having a first central axis and being arranged in the outer hollow cylindrical body (3) having a second central axis, and the two hollow cylindrical bodies each having a central axis (X1, X2), the device further comprises at least one bearing (5) for rotatably supporting the outer hollow cylindrical body on the inner hollow cylindrical body, and a hinge body (6) designed to support the inner hollow cylindrical body (4) on a central shaft (7), wherein the hinge body (6) is also designed to effect a horizontal and/or vertical angular change of the first and/or second central axis (X1, X2) relative to the central axis (X3) of the central axis, and wherein the device has a measurement and evaluation system (8) with a sensor unit (9) which is arranged inside and/or outside the guide unit (2), wherein the measurement and analysis system (8) is designed to detect the angular change.