To improve the controlling accuracy by obtaining the average of separate samplings by dividing the sum of the separate sampling information by the number of times of separate tabulation, and further obtaining the average of the sampling movement by dividing the sum of the sampling averages obtained during the average tabulation time, by the number of times of average tabulation.

A separate sampling input circuit 31 obtains the separate sampling information 2 for a separate sampling period, a separate multiplication circuit 32 multiplies a separate sampling period and the number of times of separate tabulations, to obtain the separate tabulation time. A separate addition circuit 33 operates the sum of the information 2 obtained during the separate tabulation time, a moving average circuit 3 obtains the separate sampling average by dividing the obtained sum by the number of times of separate tabulations, to transmit the same to an average sampling input circuit 51, and further an average multiplication circuit 52 obtains the average tabulation time. An average addition circuit 53 operates the sum of the sampling averages of the tabulation time, and a moving average circuit 5 obtains a sampling movement average by dividing the obtained sum by the number of times of average tabulations.