Abstract: A trench hoe-type excavator carries a digging bucket at the end of a digging device. The bucket and digging device are capable of being driven so as to maintain a set cutting angle. An indicating apparatus arranged in the field of view of the excavator operator allows the operator to check the position of the digging device to determine the direction in which the bucket must be guided in order to obtain the desired inclination and direction of the ditch floor. The indicator apparatus includes a laser transmitter and a transparent target. The transparent target is carried by the digging device and has a first surface facing the bucket operator and a second surface which is arranged to receive the laser beam from the laser transmitter. The laser transmitter is arranged on the opposite side of the target from the excavator operator, so that the position of the end point of the laser beam on the target can be observed, parallax-free, by the excavator operator during the entire digging operation.