A metal identifying device precisely identifies a metal material in a metal member having a plurality of through-hole portions penetrating through the metal member. The metal identifying device of the present invention includes a measurement unit that obtains a measurement value by measuring an electrical property and/or optical property of a test object, a threshold value determination unit that determines a threshold value with use of a reference value obtained by measuring the property of a metal member having a metal composition to be identified and information indicating a ratio of the through-hole portions to a measurement area in the test object and/or information indicating a configuration of the through-hole portion, and a comparison/identification unit that identifies a metal composition of the test object by comparing the measurement value and the threshold value.