In recent years, companies have had to change their approach to the production and consumption of goods in order to meet the requirements of sustainable development. These companies, by changing the way products are manufactured, strive to increase its efficiency, while reducing the consumption of raw materials, reducing costs and reducing their impact on the environment. An inherent element supporting such activities is the implementation of an appropriate maintenance processes. Maintenance as a business function is a crucial part in achieving the status of a sustainable company. Keeping in view the importance of maintenance, in this study the concept of sustainable maintenance criteria assessment is presented. The development of the criteria assessment method requires consideration of two aspects. First, one should determine the way data will be obtained and the method of their evaluation (e.g. index, descriptive, point). Secondly, the way in which aggregations of partial assessment should be defined within each criterion. To solve this problem the maturity matrix was used.