[en] The radio spectra of the Rosette Nebula, the source S280 and the Monoceros Nebulosity are established over a wide range of frequencies. The radio spectra of the Rosette Nebula and S280, show a typical thermal shape. Physical parameters of both H II regions are derived by adopting a spherical model. The radio spectrum of the Monoceros Nebulosity shows a non-thermal shape (sp. index - 0.66) but the exact nature of the object is not clear. Assuming it is an SNR some of its physical characteristics are estimated. (Auth.)