A method and an apparatus for monitoring the integrity of an endless sieve device (3) which is arranged to rotate around at least two spaced-apart turning rollers are described, the sieve device (3) being arranged to separate fluid and particles under a predetermined size from particles over the predetermined size, the method including the steps of: positioning at least one signal transmitter (7) at a portion of the sieve device (3) by means of a holding device (5, 5′, 5″); putting the at least one signal transmitter (7) in communication with at least one receiver (9), so that the signal transmitter (7) outputs a signal to the at least one receiver (9) at least once per turn of the sieve device (3); exposing the holding device (5, 5′, 5″) to wear; and letting the receiver (9) output a signal activating a warning device when the expected signal from the signal transmitter (7) ceases.