The church has three naves separated by semi-circular arches on pillars; the central nave is covered by a barrel vault, with groin vaults on the side naves. Although it is mostly a 19th century, neoclassical building, parts of the church are from earlier times. Legend has it that the current structure is built over a Roman palace. However, this is not the case since the oldest sector is a 15th-century Mudejar-style nave attached to the Gospel side.
Other elements predate the construction of the temple’s main hall. These include the Tabernacle Chapel (1782), decorated with plasterwork, by Antonio Matías de Figueroa, and the Sacramental Chapel in the left aisle, attached to the Mudejar nave, designed in 1770 by Ambrosio de Figueroa, which houses the Rococo altarpiece by Jesús de la Soga, and a sculpture by Montes de Oca (1732).
The neoclassical, main altarpiece is dedicated to Saint Barbara, a sculpture from the first half of the 18th century, who is accompanied by other more recent images.
Also noteworthy is the remarkable rectangular Baptismal Chapel covered by a half-dome, located at the west end of the right nave, which houses a splendid late 18th-century red and black jasper basin.
The early church had a brick tower attached to the west end of the Gospel side of the nave, next to the main façade. It had three octagonal tiers from around the fifteenth century. Owing to the damage caused by a lightning strike in 1892, it was demolished between 1918 and 1929.
This parish church has a notable collection of gold and silverwork, although most of the objects are currently in the Santa María Church. Worthy of note among the pieces preserved in situ are the 18th-century Santa Barbara’s coronet, monstrance and tower.