A rotating electric machine of the type comprising a shell housing, an active core with a rotor and a stator, and a terminal box, the shell housing shell having a terminal box receiving portion for receiving a terminal box, wherein: the terminal box receiving portion comprises an opening and, in the vicinity of the opening, two parallel spaced walls (9, 10) of which the upper edges have snap-fit beveled shoulders (11, 12); the terminal box has an engaging portion with a peripheric wall and two spaced pendant tabs (25, 26), parallel and internal to the laterals of the peripheric wall, lower edges of the two spaced pendant tabs (25, 26) having snap-fit beveled shoulders (27, 28); the attachment of the terminal box to the terminal box receiving portion is made by means of a snap fit between the snap-fit beveled shoulders (27, 28) of the spaced pendent tabs (25, 26) of the engaging portion of the terminal box with the snap-fit beveled shoulders (11, 12) of the spaced walls (9, 10) of the terminal box receiving portion, so that the two spaced pendant tabs (25, 26) are externally arranged to the parallel walls (9,10) of the terminal box receiving portion when the snap-fit beveled shoulders (27, 28) of the two spaced pendant tabs (25, 26) cooperate with the snap-fit beveled shoulders (11, 12) of the parallel walls (9, 10); the terminal box receiving portion has an inclined base and the sides of the peripheric wall of the engaging portion of the terminal box are inclined, so that the profile of the perimetric wall complements the profile of the inclined base of the terminal box receiving portion; the peripheric wall of the engaging portion of the terminal box comprises a stepped edge which cooperates with an edge of the inclined base of the terminal box receiving portion; and the cooperation between the stepped edge of the peripheral wall and the edge of the inclined base generates a shell to accommodate a gasket. the terminal box receiving portion comprises an opening and, in the vicinity of the opening, two parallel spaced walls (9, 10) of which the upper edges have snap-fit beveled shoulders (11, 12); the terminal box has an engaging portion with a peripheric wall and two spaced pendant tabs (25, 26), parallel and internal to the laterals of the peripheric wall, lower edges of the two spaced pendant tabs (25, 26) having snap-fit beveled shoulders (27, 28); the attachment of the terminal box to the terminal box receiving portion is made by means of a snap fit between the snap-fit beveled shoulders (27, 28) of the spaced pendent tabs (25, 26) of the engaging portion of the terminal box with the snap-fit beveled shoulders (11, 12) of the spaced walls (9, 10) of the terminal box receiving portion, so that the two spaced pendant tabs (25, 26) are externally arranged to the parallel walls (9,10) of the terminal box receiving portion when the snap-fit beveled shoulders (27, 28) of the two spaced pendant tabs (25, 26) cooperate with the snap-fit beveled shoulders (11, 12) of the parallel walls (9, 10); the terminal box receiving portion has an inclined base and the sides of the peripheric wall of the engaging portion of the terminal box are inclined, so that the profile of the perimetric wall complements the profile of the inclined base of the terminal box receiving portion; the peripheric wall of the engaging portion of the terminal box comprises a stepped edge which cooperates with an edge of the inclined base of the terminal box receiving portion; and the cooperation between the stepped edge of the peripheral wall and the edge of the inclined base generates a shell to accommodate a gasket.