The magnetic field was measured in a large-area microwave surface wave discharge chamber. Under certain discharge conditions the hot electron beam can be created. Charged particle flow produces a magnetic field. In our experiments we measured magnetic field intensity of 37.4 mG. This magnetic field is produced by a hot electron flux sustained in argon gas at the low pressure. The magnetic field calculated for radius of the hot electron beam 0.06 m and decay constant 0.076 m corresponds to the measured one field intensity. (c) 2005 Elsevier B.V. All rights reserved.