This article presents the exact solution of the equation of motion for a charged particle in the electromagnetic field of circularly and linear polarized multitonal amplitude-modulated waves, as well in the presence of a constant uniform magnetic field. The motion of a charged particle in the both fields was analyzed and was expressed as dependences of its average kinetic energy on the electromagnetic waves’ intensity, on their modulation percentage, on the modulation frequency-to carrier one ratio and on the constant magnetic field strength. The solution of the equation of the charged particle’s motion in the electromagnetic field of the plane wave opens up opportunities for different applications related, in particular, to various developments of multifrequency lasers and laser modulation technology. This study was undertaken in connection with the wide practical use of high-temperature plasma.