Masjed-e Jame of Saveh is one of the first mosques built in Iran and is considered as one of the valuable works of art, architecture, painting, tiling and stucco, which are all made of mud brick.
This building has undergone many changes during different historical periods that includes three historical periods of Sassanid, early Islamic and Safavid eras. Now, the mosque rectangular-square courtyard consists of a courtyard and dome (the oldest parts of the mosque) related to the fourth and fifth centuries on the south side, a tall brick minaret in the northeast corner and out of the mosque with brick decorations with no color and enamels which was in pairs but one of them remained, with stairs decorated with diverse and outstanding designs in the sixth century, some brick bedchambers from the sixth century AH and Seljuks era, two porches (western porches) in the eighth century and their restoration is related to the Qajar period.
Also, there are numerous old altars with Kufic and two other altars with Sols inscriptions from Safavid era. There are various architectural decorations on the vault and walls of the mosque with the most detailed decorations executed on the altar. There is a ruined adobe wall in front of the dome that probably has been the walls of teaching and discussion classes of seminary.