This is an internationally known instrument as it is considered to be one of the most suitable for playing the music of César Franck in a faithful manner. The installation work for this organ was undertaken under the direction of Vincent Cavaillé-Coll, brother of the famous organ maker, Aristide. It cost 228,275 reales.

It has three manual keyboards of 54 notes and one pedalboard of 27, with a total of 44 newly built stops.
It is located to the left of the choir facing the presbytery. The Organo Mayor and Recitativo organ sound in the direction of the other side of the choir while the sound of the Cadereta organ is directed towards the high altar of the church. The façade of the case corresponds to the baroque organ that had been previously installed on the same site, although the location was partially modified by Cavaillé-Coll in order to make it suitable for the requirements of the new instrument.

A peculiarity of this organ (and of others built by the same organ maker in Spain) is the great respect shown by him for the features characteristic of the Spanish baroque organ. On the one hand, Cavaillé-Coll decided to maintain the emplacement of the previous baroque organ – located to one side of the choir – and, on the other, he opted to name the manuals Organo Mayor, Cadereta or Ecos,as with the older instruments; finally opting for measuring the stops in hands and not in feet. All this can be interpreted as a form of tribute by the organ maker to the Spanish baroque organ, an instrument intricately tied to him and to his family.

Although the balanced swell pedal is located at the centre of the console, as is habitual, originally the swell pedal was operated by means of a metal lever fitted to the right of the console.

The sweetness and beauty of this organ is particularly enchanting.