The actual theoretical research investigates the resonant spontaneous bremsstrahlung (RSB) of ultrarelativistic electrons under the condition of scattering on a nucleus in the field of a weak electromagnetic wave. The progression of the functional mechanism indicates the transformation of the intermediate virtual electron into the real particle state. As a result, the initial second order process with accordance to the fine structure constant in the light field productively splits into two consequent first order formations: the laser-stimulated Compton effect and the laser-assisted scattering of an electron on a nucleus. Precise examination specifies the resonant kinematics of the RSB system that designate the phenomenon of the initial and final electrons with addendum of spontaneous high-energy photon propagation in the narrow angle cone. Furthermore, it is important to emphasize that the resonance escalation possesses a possibility to develop within two reaction channels. Thus, the first channel delineates the occurrence that correlates to the spontaneous photon emission by an electron (laser-stimulated Compton interaction) with subsequent scattering on a nucleus (laser-assisted Mott procedure). The second channel illustrates the configuration corresponding to the electron scattering on a nucleus with consecutive spontaneous photon emission in the wave field. Therefore, with implementation of the equivalent elementary criteria the value of the resonant frequency for the first channel perpetually represents a deteriorative counterpart to the second alternative. Moreover, the spontaneous photon radiation angle allocates a single-valued dependency with the resonant frequency for the first channel in contrast to the second displacement that categorizes a composite area with three various resonant frequency magnitudes for the particular emission angle diapason. The project data analysis proposes that the reaction channels do not interfere within the whole range of observation with a specific evaluation for the particles propagation at zero scattering angle. As a result of the investigation the calculations determine the scattering differential cross-section of the resonant construct development. To summarize, the particular cross-section within the resonant ambience significantly exceeds the according cross-section in the approximation of an external field absence. In conclusion, numerous scientific facilities with specialization in pulsed laser radiation (SLAC, FAIR, XFEL, ELI, XCELS) may experimentally validate the computational estimations.