A new powder simulation method that permits the large-scale of simulation of powder phenomena was developed using cellular automata. The automaton rule consists of the transition rule of constituent particles and the interaction rule between particles. The interaction rule is divided into three rules: the collision rule, the static contact rule between particles, and propagation rule of impulsive force through the particle bed. The interaction rule, which is important in the proposed simulation method, was derived quantitatively on the basis of microscopic information on the interactive force between flowing particles under gravity obtained by particle element simulation. The evolution of powder phenomena with time can be simulated by defining the equivalent time to one step in the automaton simulation, and the state variables in granular flow can be obtained by the proposed simulation method. The validity of the proposed powder cellular automaton method was confirmed by comparison of the simulated results with experimental findings: the simulated flow patterns, contact force and velocity distribution in discharging flow from a hopper agreed well with the experimental ones. The proposed powder automaton simulation method has the feasibility to simulate large-scale powder phenomena.