A new technique for pulverization of ligneous biomass by using a vibration mill was developed. By this technique ligneous biomass was pulverized into micron-order particles, and its combustibility, compatibility, reactivity and extractability were improved dramatically. With conventional pulverization equipment, it is impossible to micronize wood fiber, since it is very strong, consisting of cellulose, hemicellulose, lignin. However, by using the vibration mill, it is possible not only to control the particle size and particle shape by changing the pulverization medium, but also economically to produce micron-order particles in large quantity.