The katholikon of the monastery dates from a complete rebuilding in 1843. In plan it is the usual three-aisled basilica with a barrel-vaulted nave and flat ceilings over the side aisles, with the narthex on the west and the main semicircular apse protruding from the east end. The north aisle is named for the renowned icon displaced there—the Blessed Virgin of Consolation—surrounded by scenes from the Twelve Feasts of the Orthodox Church, an important Constantinopolitan work of the fourteenth century. The south aisle is dedicated to the Prophet Elijah, who is depicted in an icon along with fourteen scenes from his life, dated 1772. On the right side of the narthex there is a chapel dedicated to St. John the Evangelist and St. Germanos the Confessor, patriarch of Constantinople in the years 715-30.
The carved wooden iconostasis is richly decorated with floral, faunal, and heraldic motifs in perforated relief, as are the episcopal throne, the pulpit and the Oraia Pylai, or Beautiful Gates, in the center of the screen. Flanking the Oraia Pylai are icons of Christ Pantocrator, on the right, and the Virgin Hodigitria, on the left, the latter a work of the Cretan School dating from the sixteenth century. The icon of St. John the Baptist, with twelve scenes from his life, is probably also from the sixteenth century. Beneath it is the Hospitality of Abraham, which may date from the fifteenth century. Also on the iconostasis is a large icon depicting St. Photius, patron saint of the school, with an intricately worked silver covering done in Moscow in 1903. On the southern wall there is a large icon of the Virgin Hodigitria, possibly dating from the sixteenth century. Also noteworthy are the icon stands and candle stand in the narthex, all finely carved in wood with floral and heraldic motifs.
There are a number of tombs behind the church, including those of rectors and professors of the school as well as two patriarchs, Cyril VII (r. 1855-60) and Constantine V. (r. 1897-1901)
