It stands on the Domberg (Cathedral Hill) directly next to St Mary's Cathedral. As a unique architectural ensemble, both churches together form the city's landmark. Due to its unusual form, which seems to anticipate the late Gothic hall church, St Severus' Church is one of the most important Gothic buildings in Germany. The bones of the church patron Severus of Ravenna rest in an artistically very significant sarcophagus.

The present organ of St Severus' Church was built in 1930 by Johannes Klais from Bonn in the Baroque case of the Wender organ from 1714. The instrument has cone chests and electropneumatic key and stop actions.