Wikipedia says the first church on this spot was probably built shortly after Santa Fe was founded in 1610, and was first mentioned in writing in 1628. It served the mostly Native and Tlaxcalan people living in the Barrio de Analco across the river.
The Pueblo Revolt of 1680 burned the mission. When Diego de Vargas led the Spanish back in 1692, he found it burned but fixable. The church was rebuilt in 1710.
The wooden altar screen, called a reredos, was added in 1798. It holds a statue of Saint Michael that dates to at least 1709. The chapel is often called the oldest church building in the continental United States.