Abstract: A drilling apparatus for drilling underground, small diameter bore holes wherein a support frame of the apparatus is formed in part by a pair of hydraulic cylinders arranged parallel one to another. A head mounting plate that carries the drill motor is releaseably attached to a barrel portion of each hydraulic cylinder and the barrel portion is urged by fluid pressure along a support rod extending axially through the barrel. The ends of the support rods are attached by front and rear supports to form a frame that is anchored in position relative to the movable barrel.