Directional drilling device and method for calibrating the same

The invention relates to a reliably operating directional boring device for continuous operation with automatic finely controlled monitoring of the targeted boring at large depths with specification of a selectable directional course of the borehole, comprising a housing, a bit drive shaft, which preferably rotates in the housing and bears a rotary drill bit at the end of the bit drive shaft, a control device and direction control apparatuses arranged in the hull section of the housing, for producing directing forces having radially orientable force components for the orientation of the directional boring device during boring operation, and magnetic-field sensors, which magnetic-field sensors are arranged in the head section, namely in the front region of the housing which faces the rotary drill bit and is directly adjacent to the rotary drill bit and thus is closed to the drill bit, and which magnetic-field sensors can be calibrated by means of the method according to the invention by the use of a homogeneous magnetic field produced by a Helmholtz coil.