The plasma induced charging of surfaces in a plasma during semiconductor processing has been measured noninvasively using microelectromechanical devices. We have designed, modeled, and fabricated microcantilevers to act as charge sensing probes. The devices exhibit a mechanical deformation when charged, which is probedinsituby optical techniques, or measured by optical inspection after removal from plasma. Charging voltage measurements in a parallel‐plate reactive‐ion‐etching reactor show that more charging is evident at the electrode edge, and that the charging is a strong function of input rf power, chamber pressure, and flow rate of gases. ©1996 American Institute of Physics.