The submarine, dubbed Ghadir, is reportedly fitted with noise-reduction features and is capable of firing missiles and torpedoes simultaneously.
"This submarine is equipped with advanced weapons and electronics systems. It has been developed in the last decade by [Iranian] scientists and engineers," a TV program quoted Navy commander, Admiral Habib Sayyari, as saying.
The admiral also said the Navy commissioned a destroyer and a missile boat.
According to various intelligence reports, Iran has been spending a considerable share of its defense budget on modernizing its naval forces over the last decade.
"The Iranian Navy - surface ships, submarines and naval bases - is equipped with all the necessary modern weaponry, including missiles," Sayyari said. "Their [the missiles] range is sufficient to protect effectively our southern flank in the Persian Gulf."
In a separate development, Iran, which received no invitation to the Mideast peace conference in Annapolis, announced on Tuesday that it had produced a ballistic missile with a range of 2,000 kilometers (1,240 miles). The missile's range would allow it to reach Israel, as well as United States military bases in the Middle East.