Quantum confinement in two-dimensional semiconductor nanoplateletes (NPLs) is determined by their thickness which can be precisely controlled during the synthesis. As a result, NPLs have a very narrow luminescence spectrum and they can provide light sources with very high color purity. Switchable light sources needed for a wide range of applications require the dynamic control of the luminescence. One efficient approach for this purpose is direct charge injection into NPLs. In order to study charging/discharging processes and local electrical properties of CdSe/CdS core-shell NPLs as the model system, here we employed electrical methods based on atomic force microscopy (AFM). Simple and efficient procedures for “write/read/erase” operations are presented: charges are written by a biased AFM tip in contact with the NPLs, their charge state is read by Kelvin probe force or electric force microscopy, whereas injected charges are erased by inversely biased AFM tip. The amount of injected charges is well controlled by a magnitude, polarity and duration of the applied bias voltage, whereas the rate of subsequent spontaneous charge relaxation is dominantly determined by ambient humidity.