  A simple physical insight into the origin of the magnetic moment anomaly of
electron is presented. This approach is based on the assumption that the
electromagnetic mass of the electron due to the electric field generated by
electron charge in the exterior of the sphere of radius half of the Compton
wavelength of the electron, does not contribute to the magnetic moment of the
electron. This explanation is compatible with the well-known quantum
electrodynamics approach. A formula is derived, which is similar to that
obtained by quantum electrodynamics calculus of one loop contribution to
anomalous part of the magnetic moment.
