The sanctuary was built as an evangelical church in 1909 on the site of the former Dominican monastery. After the liberation of the city in 1945, the church became a Catholic church. The renovation works of 2001 restored the interior to its original condition. The church has an octagonal presbytery and a rectangular nave with balconies which is covered with a wooden barrel vault supported by a wooden column and beam structure. Above the building there is a bell tower.

What deserves special attention inside the sanctuary is the picture of the Mother of God with a Child from the second half of the 17th century – in Polish called “obraz Matki Bożej Gankowej” [in Polish ganek means cloister; the painting used to hang inside the monastic cloister] – and the Baroque cross above the altar. Both elements are the residual furnishings of the Dominican monastery which lasted in Żnin for nearly 500 years. The Stations of the Cross were made by the local artist Edmund Kapłański using the technique of marquetry. In the parish – one of four parishes of this type in Poland – there are relics of St. Gianna Beretta Molla, the patroness of families.