The permeation behaviors of submicron silica particles that were smaller than the pore size of microfiltration membranes were studied in the presence of various electrolytes with changing the concentrations. Stable permeations that maintained the initial fluxes and high permeation ratios were demonstrated when the mono-disperse submicron silica particles containing 0.1 mM sodium hydroxide (NaOH) as electrolytes were used as the feed. Under these conditions, the zeta potentials of the silica particles were the most negative, and, accordingly, the electro-repulsive effect was strengthened to avoid deposition onto the surface as well as clogging inside the pores of the membranes. A stable permeation in the presence of 0.1 mM NaOH was also demonstrated for polydisperse submicron silica particles. These results are helpful to develop a novel particle classification technique using the microfiltration membranes that we have been studying.