On the topfloor you find the Garrison Church. The Church Room is built in a New Gothic Style with the choir on the long wall and is dominated by a chandelier consisting of 276 bayonets. With its three symbols the crown, bayonets and chains it want to remind about the Royal Power, the military and the prisoners. The Church can hold up to 700 people, and was inaugurated the 1 august 1869. Until 1930 the church intended to, in the event of war, also function as the parliamentary plenary hall.
The Church belongs to The Swedish Armed Force, but is maintained by the Fortress Museum.