An electrically controlled three-way valve (1) comprising a valve body (2), within which a central cavity (3) and a respective first, second and third connection duct (4, 5, 6), adapted to bring the central cavity (3) into communication with atmosphere, are provided, and a shutter member (7) mounted to move within the central cavity (3) between a first operating position, in which the shutter member (7) is disposed to close the inlet of the first duct (4) so as to obstruct this first duct (4) in a leak-tight manner and to bring the second duct (5) into sole communication with the third duct (6), and a second operating position in which the shutter member (7) is disposed to close the inlet of the third duct (6) in order to obstruct this third duct (6) in a leak-tight manner and to bring the second duct (5) into sole communication with the first duct (4); the shutter member (7) being of spherical shape and independent from any other member of the valve (1) so that it can move freely within the central cavity (3); the central cavity (3) being shaped such that the shutter member (7) is forced simultaneously to engage the inlets (4a, 6a) of the first and the third connection ducts (4, 6), but obstructs, however, only one of the first and third connection ducts (4, 6) in a leak-tight manner.