The article presents a method developed by the authors for measuring the direction of a magnetic field using an M_Z-type quantum magnetometer, the readings of which are used to correct the frequency of an onboard small-sized rubidium atomic clock. The method was tested on a specially created experimental setup implementing an M_Z-type quantum magnetometer with optical pumping. High sensitivity of the method to a change in the angle between the optical axis of the magnetometer and the direction of the magnetic field under study for small angles was found. A conclusion was made about the applicability of the developed method for various angles limited in magnitude by the presence of "dead zones" of the quantum magnetometer.