Identification failure is reduced at the time of detecting an instrument being used. A dental instrument hanger (1) has the body of a reader/writer (40), or an antenna (42) connected to the body, arranged in a hanger unit (10) so as to read identification information from a wireless tag (T), in a state that an instrument (20) having the wireless tag preliminarily attached thereto is housed in the hanger unit. The hanger includes: an identification information storage (31) that stores in a database, for each reading history, the read identification information； a reading history detector (32) that, in response to a driving instruction having been inputted, detects with reference to the identification information storage the latest reading history and a reading history which had been read before the instrument displaced from the hanger unit has been displaced； an identification information specifier (33) that determines a difference between the two reading histories to specify the difference as identification information of a wireless tag attached to the instrument which has been instructed to drive； and a usage information generator (34) that generates usage information of the instrument.
