To improve characteristics of a semiconductor device having a nonvolatile memory. There is provided a semiconductor device having a nonvolatile memory cell that performs memory operations by transferring a charge to/from a charge storage film, wherein the nonvolatile memory cell includes a p well formed in a principal plane of a silicon substrate, and a memory gate electrode formed over the principal plane across the charge storage film, and wherein a memory channel region located beneath the charge storage film of the principal plane of the silicon substrate contains fluorine.