This altarpieces is made up of five panels, divided into compartments by a painted trompe l’oeil frame. The empty part at the bottom, probably housed the tabernacle. The only polyptych in the museum, it was acquired by Gian Giacomo Poldi Pezzoli before 1857.
The Annunciation, in the middle, is set in an interior, where the angel comes upon Mary reading. The rays of divine light and the dove, symbol of the Holy Spirit, enter through the stained glass window.
The saints are standing in pairs under a loggia which opens out onto a landscape. The rendering of the space, the depiction of the interiors, the interest in the landscape and the types of the figures show the Flemish matrix of the work.
The attribution to the Master of Saint John the Evangelist remains doubtful. This is the conventional name given to an anonymous painter, author of panels with stories of the saint now at Palazzo Bianco in Genoa.