Device for storing piece goods, in particular a shelf unit or a cupboard, having at least one shelf, which has an upper side, on which the piece good is storable in a surveillance space, and a lower side and openings, which run from the upper side to the lower side, as well as signal transmitting devices having associated signal receiving devices, wherein at least one type of the devices is arranged in the openings at the lower side, and a signal of the signal transmitting devices is detectable by the signal receiving devices, as well as a control electronics having a control system, which energize the signal transmitting devices and the signal receiving devices and process the signals of the signal receiving devices and identify them, so as to identify an occupancy state of the surveillance space with piece goods on the basis of the existence of a signal at the respective signal receiving device.