A national treasure built by third Edo shogun Tokugawa Iemitsu, the Main Hall was obliterated in the March 1945 Tokyo air raids. However, it was reconstructed in October 1958 through donations collected from adherents around Japan. Though it mirrors the original style, the current building features a solid reinforced concrete structure with titanium roof tiles.
One immediately apparent characteristic of the Main Hall is its dramatically sloping roof, quite tall compared to that of other temples, such that it can be seen from a great distance.
The 1,150 square-meter hall is divided into the naijin (inner sanctum) lain in tatami mats and the concrete-floor gejin (outer sanctum). Senso-ji's principle image, the Bodhisattva Kannon, sits on the zushi (miniature shrine) called the gokuden in the center of the naijin. The gokuden houses both the secret statue and the duplicate statue carved by Ennin, which is taken out for public viewing on December 13 of every year. It also holds images of Kannon once worn by persons of high rank including Edo period shoguns and ordained members of the royal family. To the left and right of the gokuden sit the Buddhist protector deities Bonten and Taishakuten. To the rear left of the naijin is a statue of Fudo Myo-o, and to the right is Aizen Myo-o, attendants of Bodhisattva Kannon.