We present an on-wafer measurement technique of semiconductor wafer using special coplanar microwave probes.The probe parameters are repeatable enough for S-parameter measurements and the probe life is with 100,000 contacts guaranteed.The multi-contact microwave wafer probe has been developed for on-wafer testing and sifting of GaAs integrated circuits with coplanar type.The insertion loss of microwave probe with a GSG footprint pattern is typically less than 3.0dB,and the return loss is at least 10dB at frequencies below 14GHz.