The present invention relates to an apparatus and a method for wireless purchase of merchandise from a vending machine by using a cellular mobile phone. The present invention permits a cellular mobile phone user to dial a sequence of code on the phone to invoke the vending machine to dispense merchandise, where payment is charged to the mobile phone account. The present invention also relates to an apparatus and a method for on-line inventory management. With on-line inventory management, the present invention provides high efficient operation, reduced operation cost, and just-in-time service and merchandise delivery. The present invention further relates to an apparatus and a method that allow both on-line inventory management and wireless purchase of merchandise in a vending machine.