The mass of the main asteroid belt is estimated as 13.5·10^-10 аЛ_Sun. Hidden mass does not exceed two percent of this value. It is shown that almost all asteroids with absolute magnitude H < 14 have been found up to the distance 3.8 AU from the Sun. Estimations of the masses of different zones in the asteroid belt, including the Trojans, are obtained. Perturbations, produced by the asteroid belt, excluding large asteroids, are described as the attraction of an inclined to the ecliptic plane gravitating ellipse with uniformly distributed mass.