Natural MoS₂ (001) surface structure was investigated by coaxial impact-collision ion scattering Spectroscopy (CAICISS), low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) under ultra high vacuum. It was found that the surface reconstruction of MoS₂ (001) does not occur. There is the same stacking sequence (2H structure) in the bulk. However, we found the contractions of 3.6±0.4% at the top surface interlayer (d₁₂) and of 0∼2% at the subsequent interlayer (d₂₃).