A rational examination of technical conditions in E.N.T. face and neck surgery is realized with the intention of determining the best directions of ambulatory surgery. This application is based on technical requirements due to modernization of equipment and surgical ways, specially in ear and nose surgery. In surgery of upper air and alimentary ways, patient's security is at risk. These considerations allow to discuss states in which ambulatory surgery is possible, others where it is wished and particular states where it is not recommended.