A measuring system and an associated measuring method for measuring a stator of a gearless wind power installation, wherein the measuring system has an air gap measuring unit and a position determination unit, wherein the air gap measuring unit has a holding apparatus and a distance sensor, wherein the holding apparatus is set up to mount the air gap measuring unit on a rotor of the wind power installation, wherein the distance sensor is set up to provide a signal which is indicative of an extent of an air gap between the stator and the rotor, wherein the position determination unit is set up to be mounted on the rotor of the wind power installation and to capture the signal from the distance sensor during a rotation of the rotor at a plurality of revolution positions. The measuring system and the associated measuring method make it possible to measure a stator in a simplified manner.