Optical and electronic properties of monocrystalline silicon modified by ion implantation of silver (Ag+) at energy 75keV with different concentration: D1 = 1014 ion / sm2, D2 = 1015 ion / sm2, D3 = 1016 ion / sm2 were investigated at room temperature used angularand spectral ellipsometry methods. While an experiment was carried out ellipsometry parameters Δ and ψ depends of angle of incidence (angular ellipsometry) and wavelengths (spectral ellipsometry). The refractive and absorption indexes, reflection index R(hν ) , permittivity ε (hν ) and optical conductivity σ ( hν ) were calculated using these parameters. The angular dependence of ellipsometric parameters was investigated using the serial ellipsometer LEF-3M-1 with the working wavelength 632,8 nm and a range of angles of incidence changes 65-80°. The samples' surface were explored across a broad spectral range λ=0,23 - 2,8nm (hv=0,44 - 5,39 eV) by the Beatty’s spectral ellipsometry method. In the work was compared the optical conductivity of pure Si and Si with different concentration Ag+. It is established that an increase in radiation dose observed a general shift of the bands in the direction lower energies. High intensity irradiation silver ions lead to a significant increase in surface roughness of single-crystal silicon, creating a large number of vacancies and may forms a further area at the bottom of the conduction band of silicon.