At present, Faryomad is one of the valleys in Mayami County from Shahrood City that is situated at the eastern part of Semnan Province (Iran). According to Hamdolah Mostofi, a historian, this city was the capital of Jovein County at 8th hegira century (15th AD century). During Ilkhanates Dynasty, this city was highly credible for several reasons. Name of this city has been implied in historical sources. Dolat Shah Samarghandi implied building of Faryomad Town and illustrated it as a beautiful and splendid region. Its old building may be dated from the late Seljuk era and the early Khwarazmian Dynasty (1077-1231AD). According to the existing evidence and proofs, this city has been more likely reconstructed during Khwarazmian and Ilkhanates perfectly. This building is important in terms of architectural aspect. In general, Great Mosque is an urban sign during Islamic period. Furthermore, there have some urban public areas including hospital in Faryomad. Thus, this Great Mosque has established a matrix (functional) and spatial relationship with the given city. One may deem Faryomad’s great mosque as a museum for Iranian architectural decorations in Islamic period. This mosque has double- story (Hexa- Style) porch where verandas of mosque are higher than the level of its hall. Proximity of porches together may cause lessening the area of hall in mosque. Lack of minaret or prayer’s call tower on these porches and before its entrance, the existing ceramic massive decorations with novel and beautiful geometric designs, using Kufi, Thuluth and Reyhan Scripts with moldings included Quranic verses and Islamic Traditions (Hadith), along with plant and geometric designs are some of distinct characteristics of this mosque