The IAF said on its Web site Monday that Aziz Masaadeh, 44, has been chosen in the administrative board of its branch in Amman.
It said Masaadeh, who joined the influential Islamic movement, has thus become the sole Christian leader in a group that advocates the Islamic sharia, or law, as a political, economic and social system. He joined the group five years ago.
Established in 1992 as a political party representing the Muslim Brotherhood, the IAF has widespread support nationwide.
The Brotherhood was the only politicized organization allowed to work openly during martial laws that banned all other political parties from 1957 until 1989.
The IAF has 17 members in the 110-seat elected Parliament, does not confine its membership to Muslims and opened its doors for Jordan's Christian minority.
Masaadeh's election to a top position in a fundamentally Islamic group is expected to boost the organization's image as being one that is tolerant enough to accommodate non-Muslims.