When a vending machine control system S detects a user who is about to open a door 13 of a vending machine 1 while the door 13 is locked, the vending machine control system S determines whether the detected user has a payment capability on the basis of information for settlement of the detected user. And then, the vending machine control system S controls to unlock the door 13 of the vending machine 1 in a case that it is determined that the user has the payment capability.