MEASURING APPARATUS

PROBLEM TO BE SOLVED: To shorten response time while avoiding an unstable operation, and to measure an electric parameter with high accuracy.SOLUTION: A measuring apparatus includes a filter part 4 which has an LPF4a to an LPF4c with different attenuation performance and performs filtering processing to data Dv1 on a measuring object signal S1 to be output as pieces of data Dva-Dvc, and a selector part 5 which outputs one of pieces of the data Dv1 and the respective pieces of Dva-Dvc as selection data Dv2, while calculating an effective value Drms of a measurement object signal Si and its volatility from the selection data Dv2, when the volatility is equal to or less than a reference value, calculates the effective value Drms from the data Dvc from a filter at the third stage with the highest attenuation performance, when the volatility exceeds the reference value, calculates the effective value Drms based on the data Dv1 of non-filtering processing, specifies a measurement range in which the effective value Drms is included, and after that, outputs the pieces of data Dva-Dvc in this order from the selector part 5 to calculate the effective value Drms.