In a power feeding region of a memory cell (MC) in which a sidewall-shaped memory gate electrode (MG) of a memory nMIS (Qnm) is provided by self alignment on a side surface of a selection gate electrode (CG) of a selection nMIS (Qnc) via an insulating film, a plug (PM) which supplies a voltage to the memory gate electrode (MG) is embedded in a contact hole (CM) formed in an interlayer insulating film (9) formed on the memory gate electrode (MG) and is electrically connected to the memory gate electrode (MG). Since a cap insulating film (CAP) is formed on an upper surface of the selection gate electrode (CG), the electrical conduction between the plug (PM) and the selection gate electrode (CG) can be prevented.