A semiconductor having transistors arranged side by side in one direction over a surface of a substrate and are connected in parallel. At least one passive element is disposed on at least one of regions between two adjacent ones of the transistors. The transistors each include a collector layer over the substrate, a base layer on the collector layer, and an emitter layer on the base layer. Collector electrodes are arranged in such a manner that each of the collector electrodes is located between the substrate and the collector layer of the corresponding one of the transistors and is electrically connected to the collector layer.