Abstract: A banknote reader for initiating a service operation of a vending machine comprises an installation housing of side plates and a money container. Between the side plates are modules for aligning, transporting, checking and/or rejecting banknotes. The modules are positioned at predetermined locations along the transport path of the banknotes. The installation housing has exchangeable front parts and opposite narrow sides. A flap which can be pivoted for maintenance work can be provided. A built-in control device and a connecting opening to the money container can be included.