Abstract: A composite dielectric sheet used to manufacture a multilayer electronic component. The composite dielectric sheet is flexible and has a high dielectric constant and high dielectric strength. The composite dielectric sheet contains a polyvinyl acetal resin; a high-dielectric constant filler, surface-treated with a coupling agent, dispersed in the polyvinyl acetal resin; and a crosslinking agent having two or more functional groups reactable with the polyvinyl acetal resin and the surface-treated high-dielectric constant filler. The composite dielectric sheet is suitable for use in a multilayer electronic component such as a monolithic capacitor.