The invention relates to a method of monitoring the safety of a crane, in particular of a revolving tower crane having a revolving deck, wherein the crane has a sensor system and a crane control, and wherein furthermore at least one tilt sensor is provided. In accordance with the invention, the at least one tilt sensor is attached to the revolving deck of the revolving tower crane, with the monitoring of the crane safety taking place at least during the putting up and/or taking down of the revolving tower crane.