It is generally accepted that the hidden mass of the Universe consists of massive neutrinos or other hypothetical particles (axions, photinos, etc. We assert that there is no basis for such hypotheses. Even if the neutrino possesses a mass, it would be too small, and despite the great efforts to observe the other particles, the results have been negative. If the mass distribution law f(M) M^–2 established for meteors meteorites and asteroids in the range between 10^–12 and 10²⁰ g is extended to the Universe as a whole, one obtains values for the density of the luminous matter, transparency of the galaxies and of the Universe which agree with those observed. It is assumed that the primordial deuterium was burnt up during continuous star formation, and the deuterium observed at present is of a secondary origin. It is shown that very probably the metallicity of stars of the solar type may in reality be tens of times greater than that observed in the photosphere which reflects only the metallicity of a convection layer with a thickness of less than 0.2 of the radius. The difficulties that arise if it is assumed that the dark matter consists of hypothetical noninteracting particles are mentioned: at t 10¹³ sec there cannot be any perturbations of the density of particles with mc²<20 ev="" at="" a="" level="" of="">^–4 (absence of fluctuations of the microwave background radiation); particles with mc²>10³ eV should decay during a period of 10⁸–10⁹ years and thus distort significantly the t(T) dependence; particles with mc²>10⁵ eV strongly reduce the thermonuclear synthesis time and consequently (D/H)>10^–3 and (⁴HeH)<>