The Franciscan church and monastery in Haydngasse were founded around 1386 by the arch bishop Johann Kanizsai.
In 1529 the church was destroyed by the Ottoman invaders. In 1629, after the victorious battle of Lackenbach, Count Nikolaus Esterházy had the church, which was then in rubbles, rebuilt in baroque style. In 1630 the church was consecrated to the archangel Michael and handed over to the Franciscan convent that had been founded five years earlier, in 1625.
On the inside of the church there are beautiful renaissance altars made by Italian masters, with ornate stucco decorations that go back to the original building period. On the gallery there is yet another 18th century Haydn organ. An absolute eye catcher is the rococo pulpit built in 1752. The relief represents St. Francis' fish and bird sermon.
The museum of the diocese is located on the second floor of the Franciscan monastery, which was opened to the public within the framework of a special exhibit in 1981. The east wing of the Franciscan monastery holds the princely crypt. The crypt has been designed as neo gothic column hall with a nave and two aisles with two yokes and has been extended by Ferenc Storno sen in 1856/57.