This organ, built by J. Gutschenritter was inaugurated under the name, J. Merklin et Cie. (Paris) in 1913, after a long process involving problems, disagreements and lengthy correspondence. Involved were organ maker Fernand Prince as the person mainly responsible for the work and, of course, J. Gutschenritter, himself. Very similar structurally to the organ in Andoain, this is also a beautiful and interesting, medium-sized romantic mechanical instrument, located to one side of the choir, following the tradition of the old Spanish baroque organs.

A peculiarity of this organ is that, on its construction, it had a space reserved in order to incorporate a Voz Humana and a Salicional, although one of these spaces is currently occupied by a Quincena of later construction.