A new mesoporous carbon (NMC) was prepared, and its performance in an electric double‐layer capacitor (EDLC) was compared to that of a conventional carbon (a molecular‐sieving carbon, MSC25). The effect of pore size and pore connection pattern on EDLC performance was demonstrated. To prepare NMC, phenol resin was synthesized inside the pores of an inorganic template, Mobile Composite Material 48 (MCM48), and the resulting resin‐template composite was carbonized at 700 C under Ar atmosphere. A coke‐like carbonaceous material was obtained after removing the inorganic template by HF treatment. The surface area of NMC was Formula which is smaller than that of MSC25 Formula. NMC had three‐dimensionally interconnected mesopores (2.3 nm average diam), but randomly connected cage‐like micropores (< 2, 0 nm) were dominant in MSC25. The difference in the pore size and pore …​