Electrochemical analyses of phenylthiocyclopropane derivatives and bis(arylthio)cyclopropanes were comparatively studied by cyclic voltammetric measurements. Based on the substituent effects on their oxidation potentials, a cyclopropane ring was confirmed to have a double bond system as reported. Anodic fluorination of phenylthiocyclopropanes resulted in the formation of sulfoxide and/or ring opening fluorinated products while 1,1-bis(arylthio)cyclopropanes afforded mainly desulfurizative monofluorinated cyclopropanes and sulfoxides together with ring opening fluorinated products. This is the first successful electrochemical fluorination of a cyclopropane ring.