The effect of a dc electric field on separation using crystallization was experimentally examined for the 3,5-xylenol (95 wt %) + 2,5-xylenol (5 wt %), 3,5-xylenol (99 wt %) + 2,5-xylenol (1 wt %), and 1,2,4,5-tetramethylbenzene (95 wt %) + 2,5-xylenol (5 wt %) systems. The concentration of impurity (2,5-xylenol) in the solid phase was decreased by applying an electric field for the 3,5-xylenol + 2,5-xylenol system. In the 1,2,4,5-tetramethylbenzene + 2,5-xylenol system, the electric field is ineffective at a low solidification rate. Applying high voltage, however, is effective at a high solidification rate. These results can be explained by the degree of turbulence in the liquid phase induced by the electric field.