[en] A circular planar probe of diameter 4 mm has been used to determine the ratio of the electron E x B drift speed V_d to the thermal speed V_th in the bulk plasma of a magnetron discharge. It is found that when the probe is orientated into the E x B drift, with its surface parallel to the local B-field, significantly higher electron saturation currents are detected than when the probe is orientated away from the drift (i.e. 180 degrees from this orientation). Using the electron and ion saturation current measurements and a simple model of the anisotropic plasma-probe system, which assumes both Hall and collisional cross-field transport, V_d/V_th has been determined at different positions in the bulk plasma. The maximum in V_d/V_th is found to be about 0.14 (corresponding to V_d=1.10⁵ ms^-1) and the measured distribution of drift current agrees well with data that was found in a previous study, in which V_d was determined from the knowledge of E and B, namely V_d=E x B/B², and with V_th determined from electron temperature measurements, i.e. V_th=(2kT_e/m_e)^1/2. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)