SOLEIL is the national French synchrotron, in operation since 2007: 27 beamlines provide photons to the users more than 5000 hours. For this instrument that operates a 24/7 beam and whose availability rate is of over 98%, the issue of maintenance is essential. First, it is necessary to ensure optimal operating condition because the equipment is becoming older and older. Then, preventive maintenance helps to optimize operating costs and to free up time for resources. Very implicated in this issue, SOLEIL has set up in 2011 an international Workshop, « Asset and Maintenance Management ». Then SOLEIL decided to undertake concrete actions, after having pointed out a main deficiency: the lack of a general maintenance policy. One of these actions consists in implementing a "criticality matrix", not only to identify the most critical equipment, but also to track them and to anticipate further deterioration. The objective is now to share these methods in the whole Synchrotron. So it appears that the implementation of a “maintenance management” goes through the specification of processes, organization and methods. All these parameters contribute to the excellence of the facility reputation.