A semiconductor device includes: a local memory outputting a plurality of pieces of weight data in parallel; a plurality of product-sum operation units corresponding to the plurality of pieces of weight data; and a plurality of unit selectors corresponding to the product-sum operations units, supplied with a plurality of pieces of input data in parallel, selecting the one piece of input data from the supplied plurality of pieces of input data according to a plurality of pieces of additional information each indicating a position of the input data to be calculated with the corresponding product-sum arithmetic unit calculator in the pieces of input data, and outputting the selected input data. Each of the plurality of product-sum arithmetic units performs a product-sum operation between the weight data different from each other in the plurality of pieces of weight data and the input data outputted from the corresponding unit selector.