You can use the provided lockers in the foyer. To use these lockers you need a one-euro coin. Do not use anything but a one-euro coin as substitutes usually block the mechanism. The lockers have to be empty before the end of the daily opening hours. All lockers are regularly opened and emptied out after hours.
On the first floor there are lockers as well. You receive the key by signature. You can store your own property as well as lent out books for a longer period of time.