The church has a single nave interior with two side chapels, and a dome with an octagonal tiburio; the façade is surmounted by a semicircular tympanum. The main altar preserves the sixteenth-century image of the Annunciation, but it has been repainted during the restoration works carried out in 1925 and in the 1960s. Among the artists who decorated: Giovanni Antonio Maro, Giovanni Andrea Casella, (for the stuccos), and Bartolomeo Guidobono (for the frescoes of the dome).