In this master thesis the maintenance of the AXA machining center version VHC 3-8000 XTS is analyzed which is in Đuro Đaković Termoenergetska postrojenja d.o.o. and is used for the processing of thick-walled tubing chambers of steam boilers. The company where the machining center is located is described and the organization of the company's work is analyzed with an emphasis on the maintenance department. By analyzing the state of the company and describing the existing equipment, it is estimated that the process of production is continuous and that the company is suffering great losses with every stoppage in production. The preventive maintenance activities are analyzed in the example of the AXA machining center. The purpose of preventive maintenance activities is to remove unplanned outages and failures in the machining center work. The entire organization of preventive maintenance is covered, and it includes cleaning, lubricating and maintenance of certain parts within certain time intervals, approach to the elimination of unexpected failures, the necessary documentation in maintenance department and maintenance information systems. Work in the ININ ISTEP information system is presented through the creation of work orders for preventive and corrective maintenance. At the same time, the same work orders were introduced into the MP2 Professional system with purpose of comparing information systems. The conclusion is that the selected maintenance strategy in the company meets the requirements for quality equipment maintenance, thus reducing sudden stoppages and contributing to the maintenance of high quality machining. The only drawback of the system can be discerned in the disconnected maintenance department with a warehouse and there is room for improving the information system of the company.