The invention relates to a device for digging trenches and refilling them with earth, especially for laying pipes. Said device comprises a self-propelled travelling mechanism (2), said travelling mechanism supporting a machine frame (4) with an upper structure. The device also has a boom (6) which is mounted on said machine frame (4) in such a way that it can pivot, and a shovel bucket (16). Said boom has several boom arms (8, 10, 12) which are connected in such a way that they are articulated. The shovel bucket (16) is pivotably mounted at the free end of the boom (6). According to the invention, a milling/mixing rotor (22) is located on the shovel bucket (16).