A theory of spectral parameters, dynamic conductivity, and relative integrated emission intensity has been proposed in the model of the open resonant-tunneling structure as a separate cascade of a quantum cascade laser in a transverse magnetic field. It has been shown that, according to the experiment by Blaser and colleagues, as the magnetic field strength increases to 8 T, the emission peak shifts to higher energies, while its relative integrated intensity in the strength range of 0-14 T decreases abruptly.