A processor, which executes m number of arithmetic operations in parallel, executes a partial sum instruction which takes an i-th to (i+m−1)-th elements of an input data series as input elements, so as to obtain first vector data, executes the partial sum instruction which takes a (i+x)-th to (i+x+m−1)-th elements of the input data series as the input elements, so as to obtain second vector data, and performs operations to subtract the p-th element of the first vector data and add the p-th element of the second vector data from and to a sum of the i-th to (i+x−1)-th elements of the input data series in parallel for each of the 0-th to (m−1)-th elements, so as to calculate sums of elements for m sections different from each other in parallel, and moving average processing to calculate a moving average from the sums of elements of the sections.