To remotely control the locking and unlocking of a car door easily without sacrificing security.

A communication control section 21 for a driver discriminating center 13 receives the voices of fixed words and phrases, a driver ID and signals commanding the locking and unlocking or the like of the car door from a portable telephone 12 for a driver 11. A voice recognition section 23 converts voice-input fixed words and phrases into character codes. A voice print analyzing section 24 analyzes the voice marks of input voice data and forms voice print data. A driver discriminating section 22 collates the voice-mark data of driver data to the input driver ID and the voice-mark data obtained in the voice-print analyzing section 24. When both voice-print data coincide, the driver discriminating center 13 is connected to a keyless entry device 15 for a car 14, a door lock section 33 is driven by a door lock ECU 32, and the locking and unlocking of the car door are controlled.