Mechanical and electrical properties of epoxy/silica microcomposites were investigated. The cycloaliphatic-type epoxy resin was diglycidyl 1,2-cyclohexanedicarboxylate and the curing agent was of an anhydride type. To measure the glass transition temperature (Tg), dynamic differential scanning calorimetry (DSC) analysis was carried out, and tensile and flexural tests were performed using a universal testing machine (UTM). Electrical breakdown strength, the most important property for electrical insulation materials, and insulation breakdown strength were also tested. The microcomposite with 60 wt% microsilica showed maximum values in mechanical and electrical properties.