To provide a method for obtaining the movement of particles after elastic reflection on an arbitrary reflecting surface in an anisotropic space where the movement state of electrons or holes after elastic reflection on the arbitrary reflecting surface in crystal can be calculated.

The movement state of the particles after elastic reflection is found by substituting elastic reflection occurring when power in an infinite size on the reflecting surface facing an arbitrary direction instantaneously operates in terms of time for movement, on which the force of the finite size operates in the anisotropic space where the movement energy of the particles depends on the direction of the movement quantity of the particles. Since impulse FΔ cannot directly be calculated in the case of reflection in a barrier B, the steep barrier B is substituted for a gentle barrier B' (showing a virtual reflecting surface whose inclination is constant). Since force F which the particles receive from the gentle barrier B' becomes finite, the movement of the particles on routes s and s' can be obtained by integrating hΔk/2π=FΔt.