A library apparatus includes an enclosure enclosing at least a storage cabinet. A sound sensor is located within the enclosure. The sound sensor is designed to detect sound within the enclosure. The library apparatus enables detection of sound inside the enclosure of the library apparatus. A fall of the cartridge can immediately be determined based on the detected sound, for example. If the directivity of the sound sensor has a wider range, the sound sensor is capable of reliably detecting sound caused within the entire enclosure. The sound sensor contributes to a reliable detection of a fall of the cartridge with a simplified structure as compared with an image sensor having a narrower coverage.