The invention relates to the drilling head of a deep drilling tool consisting of a tubular base element (1) having a cutting jaw (8) on one of its faces (7). On said face, the base element is fitted with cutting plates (4, 6) which can be interchangeably arranged and which are by and large cuboid-shaped, being configured quadratically when viewed from the top. The end part of the base element (1) situated on the opposite side of the face (7) has an internal thread (3) for attaching a drilling rod. The cutting jaw (8) is uninterruptedly connected to a central hollow cavity (10). The cutting plates are configured symmetrically in relation to a transverse centre plane, which makes it possible to use all eight cutting edges.