A vapor-compression refrigerant cycle device includes an ejector, a first evaporator for evaporating refrigerant flowing out of a pressure-increasing portion of the ejector, a second evaporator for evaporating refrigerant to be drawn into a refrigerant suction port of the ejector. A user authentication to judge a properness of a user of the mobile computer is carried out according to a user input based information, and the current location of the mobile computer is registered at the mobile computer management device when the user is judged as a proper user. The control signal may alternately conveys a receive mode and a transmit mode.