There is disclosed a feeding system (8) for feeding a washing unit (1) for treating empty articles (2) with empty articles (2), comprising: a conveyor (103) for advancing empty articles (2); a sensor (110), which is configured to detect the presence and/or the correct position of empty articles (2) on conveyor (103) and is configured to generate a signal in case of absence of empty articles (2) and/or wrong position of empty articles (2); a stopper (120), which is functionally connected to sensor (110) and can be displaced in a stop position, in which it prevents empty articles (2) from advancing on conveyor (103) if sensor (110) generates signal.