A low temperature storage apparatus may include a main body, a door opening and closing a storage chamber formed in the main body, a tray including storage slots receiving items to be stored, a light emitting device, a light sensing device including light receiving sensors sensing light incident on the storage slots from the light emitting device, and a controller controlling the light emitting device, receiving sensing signals, and providing status information related to the items received in the storage slots. The controller may switch the light emitting device on when the door is opened, and may sense whether or not a sensing signal is changed when the door is closed. The controller may count time from a point of change of the sensing signal if the sensing signal is changed from a signal indicating absence of a storage item to presence of a storage item, and may switch the light emitting device off when a predetermined time from closing of the door has elapsed.