Located in the apse of the cathedral, the Gothic chapel is polygonal in shape and is enclosed by two lines of stained glass windows, of which only the upper one is visible today as the other is covered by the main altarpiece of the church. Its construction began in 1388, this being considered the beginning of the construction of the main part of the Gothic cathedral.

Inside, we can see from left to right:

The Sepulchre with praying sculpture of Juan Arias de Villar, bishop of Oviedo between 1487 and 1498. It is empty as the mortal remains were transferred to the Cathedral of Segovia.

The main altarpiece, which is dedicated to San Salvador. Its construction began by order of Valeriano Ordóñez Villaquirán in 1511 by Giralte de Bruselas and was completed in 1531 by Juan de Balmaseda and Miguel Bingeles. The pictorial decoration is the work of León Picardo and to a lesser extent Alonso Berruguete. It measures 12 x 12 m and depicts 24 scenes from the life of Jesus.

The 17th century saw the construction of the ambulatory, made up of five small radial chapels. It contains the Sacristy and the Chapel of Covagonga, where the tomb of Bishop Gutierre de Toledo is located on one side, and under the altar, the remains of San Melchor de Quirós, the first Asturian saint.