SiC is a unique semiconductor material that has various polytypes and two different polarities: Siterminated Si-face and C-terminated C-face. The wetting properties of a SiC substrate mixed with 4H-SiC, 6H-SiC, and 15R-SiC were investigated by static contact angle measurement in our previous study. Recently, we prepared a thick freestanding 3C-SiC layer on the (111) plane of a dummy Si substrate using the CVD method. The free-standing 3C-SiC substrate was obtained after the etching treatment of Si wafers, and the post-wafering processes included lapping and polishing. In this study, we would like to comprehensively review the wetting properties of the principal polytypes of SiC substrates, such as 4H-, 6H-(Hexagonal, α-phase), and 15R-SiC (Rhombohedral) by newly adding the contact angle measurement of the 3C-SiC (cubic, β-phase) substrate. The measured contact angle of the Si-face was around 3º higher than that of the C-face at the 3C-SiC substrate. This trend agreed well with the previous measurement results of the SiC substrates mixed with 4H-, 6H-, and 15R-SiC regions. To investigate the effect of a native oxide layer on the 3C-SiC substrate, the native oxide layer was removed using BOE treatment. We periodically measured the contact angle on both polarities of the 3C-SiC substrate up to 24 hours after the removal of the native oxide layer. The static contact angle of both polarities of the 3C-SiC substrate showed a gradual increase and approached the initial value before BOE treatment within 5 hours. This implies that a native oxide formation process (surface passivation) occurs more rapidly even at both polarities of the 3C-SiC substrate at room temperature. Furthermore, this result can be explained by the higher surface energy of both polarities of 3C-SiC, which is twice as much as that of the other SiC polytypes. The oxidation rate of the SiC substrate is largely affected by its surface energy and hexagonality of both polarities. To elucidate the difference in surface energy among SiC polytypes, the hexagonality of each SiC polytypes depending on the Coulomb’s potential energy and interatomic distance was discussed.