Abstract
Investigating the elementary process of diffusion yielded the universal expression of diffusivity relevant to the angular momentum of each microparticle in a material. Using the diffusivity obtained then for the diffusion equation, the wave equation of Schreadinger was theoretically derived from the physical concept in Newton mechanics. The derivation itself reveals that any moving microparticle has the wave image as an intrinsic nature. It was theoretically revealed that the relation having been accepted as a hypothesis proposed by De Broglie is really valid for any moving microparticle and also that another relation of matter-wave is possible. The new diffusion theory based on the matter-wave will be useful for further development of the nanotechnology in materials science.