Apostolic vicariate
Saiz was born in Revilla del Campo, Spain, and ordained a priest on 13 March 1937 of the Order of Friar Minor. He was appointed Apostolic vicar of Requena, Peru on 26 November 1973 as well as Titular bishop of Simingi. Pérez retired as Apostolic vicariate of Requena, Peru on 15 May 1987.