A new tool for surface structure analysis, thermal diffuse scattering (CTDS), is reviewed. The principle of CTDS is based on a very simple diffraction phenomenon, which is induced by a strong vibrational correlation between neighbor atoms, and could be considered as a diffraction of nearest neighbor atoms. Simple intensity oscillations are experimentally corrected by the medium energy electron diffraction with a very-grazing-incidence condition. Accurate bond lengths and bond orientations are obtained from a three-dimensional Patterson function, which is a Fourier transform of the CTDS pattern, i.e. the simple intensity oscillation of thermal diffuse scattering. The potentia of CTDS as a direct surface structural tool has been reviewed with an application to a Si(111)√3×√3-In surface.