We investigated r.f. sheath width variation in transversely magnetized capacitive coupled plasma. While increasing the magnetic field, a paradoxical sheath width variation was observed. Although the electron density decreases with increasing magnetic field, the r.f. sheath width (S-0 alpha1/rootn(e)) decreases with increasing magnetic field. This paradoxical result originates from the overlooking of the axial electron density profile variation by the magnetic field. (C) 2003 Elsevier Science B.V. All rights reserved.