We have investigated the wet classification of a submicron silica particle using the counter-and orthogonalelectrophoresis method. The counter-electrophoresis method is a classification technique to move particles in the opposite direction with respect to their gravitational settling direction using electrophoresis. In contrast, the orthogonalelectrophoresis method is a technique to move particles using electrophoresis in the orthogonal direction with respect to the flow direction of the slurry. In order to examine the effectiveness of these two methods, two types of slurry were prepared: an ultrasonicated silica slurry with a constant electrophoretic mobility regardless of the particle diameter and a bead-milled silica slurry in which the absolute value of the electrophoretic mobility increases with the increase in the particle size. The results revealed that understanding the electrophoretic characteristics of the slurry and selecting a suitable classification method are important parameters for conducting wet classification using electrophoretic phenomena.