Bognor Regis Library is now closed temporarily.
The London Road facility is shut for three weeks.
The temporary shutdown is to enable self-service machines to be installed.
Readers can use other nearby branches such as Willowhale in Rose Green, Chichester or Littlehampton.
The new machines will be quick and easy to use and will mean an end to queues for borrowing items.
They will also enable lists of loaned books to be printed, check when an item is due for return and make cash payments.