Precise and quantitative evaluation of the semiconducting (or metallic) purity of single-wall carbon nanotubes (SWCNTs) is extremely significant, not only for obtaining an indicator on their separation process development, but also for the property analysis in their electronic applications. In this work, electrostatic force microscopy (EFM) was applied to quantify the semiconducting (s-) type purity for as-grown and separated SWCNT samples. Count-based and length-based analyses for hundreds of SWCNTs observed in EFM images were carried out. By analyzing 1826 SWCNTs of as-grown sample based on the count, the s-type purity was estimated around 77.8 %. On the other hand, the length-based analysis showed the s-type purity of 67.3 %. The latter result, suggesting approximately equal to the semiconducting purity of SWCNTs with a random chiral distribution, is probably because the length-based analysis provides weighted statistics that is more suitable for the quantitative evaluation, and supports the validity in terms of precision. Furthermore, it was also demonstrated that the length-based EFM analysis for 850 SWCNTs of s-type enriched SWCNTs showed the s-type purity of 98.6 %.