A method and device for maintenance of an elevator installation or an escalator installation communicates the presence of a maintenance technician at the elevator or escalator installation to a remote service center. The service center is thus informed about that the maintenance technician has to maintain or is maintaining or has maintained a specific installation and is in a position of checking the quality of this maintenance. The maintenance operations are recorded as a maintenance record and communicated to the service center. For example, the maintenance record contains details about which maintenance technician on which day of the year and for how long has undertaken which maintenance operations on a specific elevator or escalator installation. The quality of a thus detected maintenance can then be compared with a quality standard. In addition, the maintenance operations performed are thus uniquely detected and can be evaluated.