The effect of an electric field on the concentration of impurity in the solid phase for 3,5-xylenol + naphthalene system was experimentally examined by applying a die. electric field parallel to the solid-liquid interface during normal freezing solidification. The concentration of impurity (:naphthalene) in solid 3,5-xylenol was decreased by the electric field (applied voltage = 1800 V; electric field strength = 6000 V/cm). Furthermore, normal freezing solidification of pure 3,5-xylenol was performed. The density of solid 3,5-xylenol, which was taken from between electrodes, was larger than that applied with no electric field. The degree of transparency became higher by applying the electric field. These results show that naphthalene as an impurity and air bubbles in solid 3,5-xylenol can be reduced by the electric field during normal freezing. These may be due to turbulence in the liquid phase induced by the electric field because naphthalene or dissolved air near the solid-liquid interface can be removed by turbulence during normal freezing.