A basic research is being carried out on transport of particles and particle size classification in electrostatic traveling field. A particle conveyor consisting of parallel electrodes was constructed and four-phase traveling electrostatic wave was applied to the electrodes to transport particles on the conveyer. The following were clarified by the experiment and numerical simulation with the Distinct Element Method: (1) Particles were transported almost linearly with time. A transport rate was also linear with the applied voltage but a threshold existed due to adhesion force. (2) The direction of particle transport did not always coincide with that of the traveling wave but partially changed depending on the frequency of the traveling wave, the particle diameter, and the electric field. Particles were vibrated but not transported under high frequency field. (3) Particles were efficiently transported under conditions of low frequency, high voltage, and the application of rectangular wave. (4) Particles were classified with size under the voltage application of appropriate frequency.