Abstract: The present invention relates to a drilling apparatus provided for drilling away an existing underground pipe and for replacing it with a new pipe. The apparatus comprises a tubular body; a percussive drill bit slidably connected to an end of the tubular body where the drill bit is capable of reciprocating movement with respect to the tubular body; a device for moving the percussive drill bit with respect to the tubular body to perform drilling operations at a drilling location; a guiding element fixedly connected to the tubular body and axially passing through the tubular body and the drill bit to connect, in a direction of travel of the drilling apparatus, to a device causing the advancing movement of the tubular body. The guiding element and the percussive drill bit are axially movable relative to each other to prevent impacting movements from the drill bit from being transmitted to the guiding element.