We measured temperature dependence of a spin polarization of field-emitted electrons from a single-crystalline magnetite (Fe3O4) whisker with < 1 1 0 > orientation. The spin polarization of emitted electrons began to increase above 130 K corresponding to the temperature of Verwey point (T-v). The increase is considered as reflection of the change of the spin state near the Fermi level due to the Verwey transition. Our experimental results support a localization of t(2g) orbital electrons below the Verwey point and a model of charge ordering for magnetite. (C) 2009 Elsevier B. V. All rights reserved.