Conjugated microporous polymer (CMP)‐based energy‐storage materials were developed for pseudocapacitors. Nanoparticulate CMP (N‐CMP) with an average diameter of 41±4 nm was prepared through kinetic growth control in the Sonogashira coupling of 1,3,5‐triethynylbenzene with 1,4‐diiodobenzene. The N‐CMP is rich in a diphenylacetylene moiety in its chemical structure. Through the FeCl3‐catalyzed oxidation of diphenylacetylene moieties, N‐CMP with benzil moieties (N‐CMP‐BZ) was prepared and showed enhanced electrochemical performance as an electrode material of pseudocapacitors, compared with CMP, CMP‐BZ, and N‐CMP. In model studies, the benzil was redox active and showed two‐electron reduction behavior. The excellent electrochemical performance of N‐CMP‐BZ is attributable to the enhanced utilization of functional sites by a nanosize effect and the additional redox contribution of benzil moieties.