Abstract Scanning nonlinear dielectric microscopy (SNDM) has improved significantly, achieving low-concentrated observations. Therefore, it is of great interest to observe how adsorbed water and other measurement environments influence SNDM measurements so that the material's dielectric properties can be detected. This study investigates how specific measurement environments, namely air, dry nitrogen, and vacuum environments, influence the SNDM and C-V curve measurements of semiconductor samples. The p-n structure created by ion implantation was measured by applied-DC-voltage SNDM, and in these environments, the corresponding C-V curves were obtained. As with the p-n structure sample, an abnormal result was obtained when a positive DC voltage was applied to an epi-Si sample in air. A low concentration level was clearly measured in vacuum. From these results, it can be concluded that measurement in a high vacuum is an effective way to obtain highly precise carrier distributions.