Soltanieh's credentials have reportedly already been delivered to the office of IAEA head Muhammad el-Baradei.
Soltanieh will travel to Vienna to take up his post after the New Year holiday. He replaces Mohammad Mehdi Akhondzadeh.
Iran remains locked in a dispute with the international community over its nuclear program. The IAEA's board of governors recently criticized Iran for failing to provide full disclosure about its program.