An N-type source region and an N-type drain region of N-channel type MISFETs are implanted with ions (containing at least one of F, Si, C, Ge, Ne, Ar and Kr) with P-channel type MISFETs being covered by a mask layer. Then, each gate electrode, source region and drain region of the N- and P-channel type MISFETs are subjected to silicidation (containing at least one of Ni, Ti, Co, Pd, Pt and Er). This can suppress a drain-to-body off-leakage current (substrate leakage current) in the N-channel type MISFETs without degrading the drain-to-body off-leakage current in the P-channel type MISFETs.