The invention provides electronic parts which comprise a composite dielectric layer composed of an organic insulating material and a dielectric ceramic powder having a larger relative dielectric constant than the organic insulating material, and which also comprise conductive element sections forming inductor elements, etc., wherein the organic insulating material comprises a cured resin obtained by curing reaction of an epoxy resin with an active ester compound obtained by reaction between a compound with two or more carboxyl groups and a compound with a phenolic hydroxyl group. The dielectric ceramic powders of the described electronic parts have larger relative dielectric constants than the organic insulating materials, and the organic insulating materials have low dielectric loss tangents. It is possible to adequately reduce time-dependent dielectric constant changes in the high-frequency range of 100 MHz and above even with prolonged use at high temperatures of 100° C. and higher, while it is also possible to satisfactorily prevent deformation and other damage to the electronic parts during their handling.