A nanoresonator based on a graphene layer is investigated as an electromechanical oscillatory system. Mechanical oscillations are excited in it by a high-frequency alternating electric field. A nanoresonator is considered as a capacitor with kinematically varying capacity of the determined transverse deformation of the graphene layer as one of its plates. In the case of small ratios of energy accumulated in a capacitor to the amplitude of energy of mechanical oscillations and the time constant of the capacitor charge to the period of free oscillations, excitation of both common and parametric resonances is possible. It is shown that upon decreasing the external frequency lower than the half-frequency of free oscillations, the cessation of forced oscillations of the nanolayer is observed. This makes it possible to determine more reliably the variations in the intrinsic frequency of the nanoresonator upon deposition of a nanoparticle on it.