In this paper we use the model of extragalactic background light to investigate the factors that have influence on the confusion noise. It was shown that (1) Large-Scale Structure of the Universe is an important factor; (2) gravitational lensing does not have a significant effect on the confusion noise; (3) lower redshift limit of objects that contribute to the confusion noise does not depend on the wavelength and is about z min ∼ 0.5 − 0.6, while upper redshift limit gradually changes from ∼ 4 to ∼ 3 with the increase of wavelength from 70µm up to 2000µm; (4) at rather short wavelengths ( 70µm) galaxies with luminosities in the range 10 7 L -10 9 L give the most contribution to the confusion noise, while at larger wavelengths (650-2000µm) their luminosities are greater than L ≥ 10 10 L ; (5) contribution from objects with different color characteristics is considered; (6) the variability of the extragalactic background on the timescale from 1 day to 1 year is noticeable at short wavelengths (70-350µm) and manifests at fluxes < ∼ 1 mJy.