A conveyor belt aligning device (1) comprising a support frame (2) mounted on a support beam (3) and being substantially horizontal pivotable about a first axis (4), the support frame (2) comprising a frame formed by a cross member 96) and a lever arm (8) extending from the cross member (6); at least one conveyor belt support roller (10) mounted on the cross member (6); a guide roller (14, 15) mounted on a transverse beam that is pivotably mounted on the lever arm (8); the transverse beam (16) being pivotable about a second axis (18); a stay member (20) extending between the support beam (3) and the transverse beam (16). The conveyor belt aligning device further comprising adjusting means for adjusting the distance (19) between the first axis (14) and the second axis (18) and adjusting means for adjusting the distance between the second axis (18) and a central axis (26) of rotation of the guide roller (14, 15).