A new measuring method of powder flow rate in gas-solids pipe flow was developed and investigated both theoretically and experimentally. The method is based on the static electrification of particles by their impaction on the inside wall. The powder flow rate was successfully calculated by use of the electric currents generated from the wall to the ground. It was found that the effect of initial charge of particles on the measurement could be eliminated by using two metallic pipes whose inner-surfaces were coated with different materials. It was also found that the powder flow rate and the mean particle charge could be measured simultaneously.