Magnetic-structure distortions near the antiferromagnet surface produced by a magnetic field are studied theoretically. Both compensated and uncompensated surfaces are considered. The characteristic depth to which the distortions penetrate into the antiferromagnet is calculated, and the dependence of this depth on the magnetic field strength is studied over the entire range of magnetic fields up to the field at which the magnetizations of the two antiferromagnet sublattices become aligned with the external field. The surface magnetic moment associated with these distortions is found. (c) 2005 Pleiades Publishing, Inc.