An electronic instrument is adapted to communicate with another electronic instrument. The electronic instrument includes an acquisition section, a storage section, an inquiry section and a processing section. The acquisition section is configured to acquire identification information from a managed article used by the electronic instrument, the identification information being read-only information uniquely assigned to the managed article. The storage section is configured to store the identification information acquired by the acquisition section. The inquiry section is configured to inquire another electronic instrument as to whether the identification information acquired by the acquisition section is already stored in another electronic instrument. The processing section is configured to perform processing in response to a result of inquiry by the inquiry section.