The changes in voltage-induced magnetic anisotropy were investigated in an epitaxial magnetic tunnel junction structure. Perpendicular magnetic anisotropy of the ultrathin FeCo layer could be confirmed from thesaturation properties of the TMR curve measured under in-plane magnetic fields. The aturation field was clearly changed by the application of bias voltages, which implies that the change in voltage-induced anisotropy was achieved in the magnetic tunnel junction structure.