The Gasthuiskerk is an aisleless church in a late Gothic style, with a straight closed choir and a narrow, asymmetrically positioned tower of three sections with a constricted spire. The church, originally named St.Antoniuskapel, was probably built at the beginning of the 15th century and was part of a guest house which was founded between 1337 and 1354. The tower was added in the middle of the 15th century. Originally, the church had a side-aisle running along the full length of the north side, but most of it was removed at an unknown time. The arches between nave and side-aisle were closed.

After the Reformation the building was left without a use for a while. During the French occupation (1672-1674), when the St. Martinus temporarily was in catholic use, the Gasthuiskerk was a reformed church. In 1707 it served as a prison for French prisoners of war. The reformed returned to the Gasthuiskerk in 1717, after the roof of the St. Martinus collapsed. Since 1735 the building has been in use as a Lutheran church, but today it's mostly used for cultural events. In 2013 a glass extension was added at the north side.