Abstract: A molded material including a fibrous organic compound and a matrix including a resin having rubber elasticity reinforced with the inorganic filler are composited to form a composite sheet with an internal porosity is 10% or less, a specific gravity of 1 to 2, and a thermal conductivity in a thickness direction of 0.4 W/mK or more. The composite sheet has both electrical insulation property and thermal conductivity, is superior in heat resistance and flexibility, and can be used in electrical apparatus with improved heat dissipation characteristic.