Chemo-mechanical polishing (CMP) is widely applied to produce the surface with outstanding global planarization before the epitaxial growth of the 4H-SiC thin film on the wafer. However, it has been reported that scratch-like surface defects consisting of rows of step bunching locally sometimes appear on the wafer surfaces after epitaxial growth on these surfaces even though there are no visible surface defects on the wafers after the CMP process. It has been elucidated that the rows of step bunching were caused by crystal defects which are introduced newly in the subsurface regions of the wafers during the CMP and remain after the CMP. The polishing damage consisting of crystal defects sometimes remains in subsurface regions of wafers after CMP even in recent years. They are barely detected by conventional optical microscopy. Mirror projection electron microscope (MPJ) can visualize slight potential change due to the surface morphology of the epitaxial layer and local charging of the crystal defects beneath the surface. Therefore, MPJ is one of the most powerful tools to inspect the distribution of such polishing damage, which cannot be detected using optical microscopy, over the whole wafer. However, the relationship between contrast formation in the MPJ images and the distribution of crystal defects in polishing damage is not yet thoroughly understood. The present study aimed to analyze the detailed structure of the polishing damage and reveal the relationship between the MPJ image contrasts and the defect structures. First of all, polishing damage locally remaining beneath the surface regions of the 4H-SiC wafer after CMP was non-destructively inspected by using MPJ. From MPJ images of polishing damage A, B, C, D and E, the inside and outside of the line contrasts of every polishing damage in the MPJ images were dark and bright contrast, respectively. The width and intensity of the line contrasts were different for each polishing damage. The widths and the contrasts of polishing damage A, B, D and C, E were wider and higher than those of polishing damage C and E. The widths of A, B, D and C, E were from 3.0 to 3.5 um and from 2.2 to 2.5 um, respectively. The plan-view TEM images of polishing damage A, B, C, D and E revealed that high-density dislocation loops were generated along local plishing damage line. The spreads of the crystal defects in polishing damage A, B, D and C, E were from 130 to 210 nm and from 50 to 70 nm, respectively. The result shows that there is correlation between the spreads of the crystal defects and the widths of the line contrasts in MPJ image. From, cross-sectional STEM images of polishing damage A, B and C, there was no significant difference between surface roughness of each plishing damage. In conclude, It is conceivable that MPJ detects the distribution of crystal defects in polishing damage more preferentially than the surface roughness.