The invention relates to a drilling apparatus for working the ground comprising a drill drive for driving a drill string in a rotating manner and a rotary feedthrough for passing a construction material from a construction material hose into the interior of the drill string, whereby the rotary feedthrough has a first line connection for the construction material hose and a second line connection, rotatable relative to the first line connection, for the drill string. In accordance with the invention provision is made for the rotary feedthrough to have a rotary device for actively rotating the second line connection relative to the first line connection. The invention also relates to a method for working the ground, which can be carried out, in particular, by means of a drilling apparatus according to the invention.