An arithmetic processing device includes: a processor that issues a store command and a load command; and a memory coupled to the processor, wherein the processor: includes a cache memory which stores data to be stored corresponding to the store command and a buffer including entries which stores the data to be stored; searches, in a case where the load command is issued, the entries; and selects, when data to be loaded corresponding to the load command is present in the entries, the data to be loaded from the buffer.