The invention relates to a method for measuring a state of wear of a consumable friction element, a measuring apparatus and a friction element (10), in particular a brush (11) or the like, wherein: the measuring apparatus has a sensor device with a sensor; by means of the sensor a magnetic field can be produced; the friction element can be moved in the magnetic field relative to the sensor; the measuring apparatus has an indicator (18); the indicator can be mounted on the friction element; the indicator comprises a ferromagnetic, antiferromagentic and/or ferrimagnetic material; and by means of the sensor device a change in the magnetic field as a result of a change in the position of the indicator relative to the sensor can be detected.
