A method of manufacturing N-type MOSFET includes: implanting a p-type dopant into in a surface layer of a semiconductor substrate to form a channel region; forming a gate insulating film including High-k material and a gate electrode on said channel region; implanting a p-type dopant into both ends of said channel region in an inner portion of said semiconductor substrate to form halo regions; implanting a p-type dopant into both ends of said channel region in a surface layer of said semiconductor substrate to form extension regions. One of said step of forming said channel region and said step of forming halo regions includes: implanting C into one of said channel region and said halo regions. An inclusion amount of said High-k material is an amount that increase of a threshold voltage caused by said High-k material being included in said gate insulating film compensates for decrease of said threshold voltage caused by said C being implanted.