We have investigated diffusion of spherical surfactant micelles in fluid and crystal phases. The short-time and the long-time collective diffusions of spherical micelles were addressed by a neutron spin echo (NSE) and a dynamical light scattering (DLS) technique. In the fluid phase, the first-order virial coefficients of the normalized short-time collective diffusion coefficients agreed with those of the hard spheres, whereas the long-time collective diffusion coefficient exhibited the characteristic slowing down toward the fluid-HCP transition. At the fluid-HCP transition, the short-time diffusion coefficient increased abruptly, indicating increase of the effective free volume available for the micelles. Simultaneously, we observed a very slow mode characteristic of the crystal phases, suggesting hopping of micelles among the lattice sites.