A field device includes one or more processors configured to perform a first processing with reference to safety-critical data and a second processing with reference to safety-uncritical data which is less critical than the safety-critical data, wherein the one or more processors are configured to generate a first request for storing the safety-critical data in the second processing, store the safety-critical data into a storage unit in the first processing in accordance with the first request, and store the safety-uncritical data into the storage unit in the second processing.