In this paper, we present the first successful observation of single electron charging events in an individual InAs QD by spectroscopic measurement with a 4.5K vacuum non-contact AFM (NC-AFM). The main features of the experimental results agree with a simple theory based on the semiclassical theory of the Coulomb blockade effect.@footnote 1@ The sample structure consists of a two dimensional electron gas (2DEG) layer used as a back electrode. The uncapped InAs QD were grown on top of a InP spacer layer serving as a tunneling barrier. The resonant frequency shift and the dissipated energy of an oscillating AFM cantilever were measured as a function of the tip-back electrode voltage, and the resulting spectra show distinct jumps when the tip was positioned above a QD. The observed jumps in the frequency shift, with corresponding peaks in dissipation, are attributed to a single-electron tunneling between the dot and the back electrode governed by the Coulomb blockade effect, and are consistent with a model based on the free energy of the system. The observed phenomenon may be regarded as the force version of the Coulomb blockade effect. The peaks in dissipation are essentially due to a single electron back action effect on a micromechanical transducer. This NC-AFM based technique has several advantages: It does not need any leads to be attached to individual QD and is also much less invasive for the mesurement of quantum states in the QD because only weak, controllable coupling between the tip and the QD is required. @FootnoteText@ @footnote 1@ Stomp et al., Phys. Rev. Lett. 94, 056802 (2005).