The building, in the bourguignon Gothic style that is characteristic of Sagrera, is especially noteworthy for the architectural design of a rectangular room with two entrances. Its inside is divided into three naves and twelve aisles by six slender spiral columns with rib vaults. One of the original features of the building is at the bottom of the ribs, which blend into the columns at different heights and are embedded into the walls on the sides.
The most striking feature on the outside are the four octagonal corner towers and the ten smaller ones that act as buttresses, due to the decoration of their windows and the splendid sculptures. The most important sculpture work includes the figures on the tympanums of the portals (the Ángel de la Mercadería (Angel of Merchants) over the main portal and the Madonna with the Child over the garden portal). The angular towers have sculptures of Saint Claire, Saint Catherine, Saint John the Baptist and Saint Nicholas (currently lost). It is also important to note the angels on the tracery of the windows and the vault keystones.
The inside is open to the public only if there are temporary exhibitions.