A field device, which measures a physical quantity in a plant or processes the physical quantity, includes: an instruction unit configured to output a verification execution instruction signal for instructing execution of verification of the field device; an operation verifying unit configured to verify an operation of at least one element of the field device in response to the verification execution instruction signal and to verify an operation of the field device based on the verification result; and an output unit configured to output the verification result which is a result of verification of the operation by the operation verifying unit.