The vending machine monitor has a sensor to determine the product level in a storage chute. The sensor is connected to a control unit connected in turn to a communication modem. The latter transmits data from the sensor to a remote central unit. The modem is pref. a telephone modem connected to the central unit by a radio link or link wire. Pref. the control unit has an automatic call unit which actuates the modem when a set min. product level is reached. Pref. additional sensors are used to monitor technical aspects of the machine.
