An LC composite component has a unique structure that makes it easy to set frequency characteristics while reducing a circuit area and the number of layers. The LC composite component includes a laminated body including a plurality of dielectric layers. The laminated body is produced by forming input and output electrodes and an LC resonant circuit therein. The LC composite component includes a capacitor, which includes an elongated electrode portion having an elongated shape. The elongated electrode portion faces a flat electrode portion having a flat shape, with one of the dielectric layers interposed therebetween. At the same time, the elongated electrode portion constitutes an open stub that is open at a tip end.