An ion beam absorbing apparatus for an ion implanter comprises an ion absorber for absorbing ions in an ion beam generated by the ion implanter, and support means for supporting the ion absorber and adapted for connection with the ion implanter, so that when so connected, the ion absorber can intercept the ion beam and absorb ions not intercepted by a target to be implanted with beam ions. The support means is further adapted for supporting the ion absorber in a plurality of different positions which can be selected so that respective different parts of the ion absorber intercept the ion beam.