Abstract: The invention is directed to a semiconductor device which is manufactured by a BiCMOS process in which a process of manufacturing a V-NPN transistor is rationalized. Furthermore, the hFE of the transistor is adjusted to a large value. An N type base width control layer is formed being in contact with a bottom portion of a P type base region under an N+ type emitter region. The N type base width control layer shallows a portion of the P type base region under the N+ type emitter region partially. The P type base region is formed by using a process of forming a P type well region, and the N type base width control layer is formed by using a process of forming an N type well region, thereby achieving the process rationalization.