Hydration of a spherical micelles of C12E6 in solution is studied by molecular dynamics simulation. The interface is found to be separated in an inner part composed of water and hydrophobic and hydrophilic moieties and an outer part with hydrophilic moiety and water only. Hydration numbers in the inner and in the outer parts are in excellent agreement with experimental data from various different methods. Temperature dehydration occurs in the inner region only and is related to the presence of water molecules directly in contact with the hydrophobic core at low temperature.