A semiconductor device facilitates keeping all parasitic resistance values between contact portion of a common source (V.sub.cc) line and intrinsic collector operation regions of respective transistors small enough so as not to exceed predetermined values and so as to be nearly identical. The parasitic resistance values are made small and nearly identical by disposing collector electrode connecting layers between base impurity introducing layers of respective transistors provided with predetermined intervals in a semiconductor substrate. Because of this arrangement to minimize and equalize resistances, the voltage drops generated by the parasitic resistances applied to respective transistors are suppressed so as to be lower than or not substantially exceed the operation threshold voltages of the parasitic transistors.