Abstract: In one aspect, the present invention provides a method of managing fluctuations in power supplied to a semiconductor processing apparatus that includes monitoring the power supplied to the apparatus to detect the occurrence of a power fluctuation event during a semiconductor processing session. Upon detection of a power fluctuation event, the semiconductor processing can be interrupted. After the end of the power fluctuation event, at least one operational parameter of the apparatus, e.g., vacuum level in an evacuated processing chamber, can be measured, and the semiconductor processing can be resumed when the measured operational parameter is within an acceptable range. The measured operational parameter can preferably include a parameter that recovers more slowly than others when adversely affected by a power fluctuation event.