We successfully measured the mechanoluminesence (ML) from a single ML nanoparticle at the first time. In order to measure the weak light emission from a single nanoparticle induced by applying a micro force, we developed an AFM-based new apparatus with a photomultiplier. Interestingly, the emission (ML) intensity from a nanoparticle was approximately proportional to the load, the phenomena is similar to the macroscopic ML emission properties.