This paper presents a descending method to classify Boolean functions in 7 variables under the action of the affine general linear group. The classification determines the number of classes, a set of orbits representatives and a generator set of the stabilizer of each representative. The method consists in the iteration of the classification process of RM(k, m) / RM(r- 1 , m) from that of RM(k, m)/RM(r, m). We namely obtain the classifications of RM(4, 7)/RM(2, 7) and of RM(7, 7)/RM(3, 7), from which we deduce some consequences on the covering radius of RM(3, 7) and the classification of near bent functions.