Detection of material and filling state of empty containers

There are proposed a method and a device for detecting the material and the state of filling of empty containers in reverse vending machines. The method is characterized in that it is determined whether the weight of an empty container (4) is below a predetermined weight threshold value, that the empty container is irradiated with light emitted from an illumination device (5) is emitted, and that the light after the transmission through the empty containers (4) by means of a transmitted-light sensor (6) on which the illumination device (5) side facing away from the empty container (4) is detected. The apparatus for carrying out the method is equipped with a pressure sensor (2) for determining whether the by the weight of an empty container (4) to the pressure sensor applied (2) pressure is greater, equal to or less than the predetermined pressure threshold, and an optoelectronic transmitted light sensor (6) for detecting the state of filling of an empty container (4).