On the outside, the only decorative element is the wooden doorway, above which there is an alcove sheltering a statue of Saint Martin dressed as the Bishop of Tours.
Inside, the main altarpiece, sculpted in the latter quarter of the 17th Century by Jacques-Antoine Todesco and Guillaume Moulin, has kept its original uniformity. There are three paintings in its centre : Saint Martin on horseback sharing his cape, and, on either side, Saint Sebastian and Saint Joseph.
Above, in a frame of two pilasters and two twisted columns, a painting with sculptural depth represents the Assumption of Virgin Mary, carried by four angels. The main altar is covered in Cordue leather.
At the top of the right nave, one finds the Rosary altarpiece, representing the Virgin holding out the chaplet to Saint Dominic, surmounted by fifteen small medallions depicting the mysteries of the Rosary.
The top of the altarpiece in the left nave features a representation of Blessed Paul, dated 1763. This Spanish pilgrim died from exhaustion in January 1721 near the Lac du Lou while he was trying to reach Rome via the Alpine passes. His body, found after the snow melted, was mysteriously intact which earned him the status of Blessed. To this day he is buried under the church altar.
The vault is decorated with frescoes in the centre of which one can recognise the four Evangelists. With the polychromy, gilding, the abundance of decoration and the profusion of details, Alpine Baroque Art offers worshippers a picture image of religious history, ideal for lifting up spirits. This was also, for the very catholic Savoy, a way to resist, with beauty, against the austerity of Calvinism.