A nonvolatile semiconductor memory that allows simultaneous implementation of high performance transistors in a low-voltage circuit region and transistors with high withstand voltages in a high-voltage circuit region. The nonvolatile semiconductor memory includes a cell array region that comprises aligned memory cell transistors, each including a control gate electrode, which includes a metal silicide film, an inter-gate insulating film below the control gate electrode, a floating gate electrode below the inter-gate insulating film, and a tunnel insulating film under the floating gate electrode; a high-voltage circuit region arranged in a periphery of the cell array region and including a high voltage transistor, which includes a first gate insulating film thicker than the tunnel insulating film; and a low-voltage circuit region that is arranged in a different position than the high-voltage circuit region arranged in the periphery of the cell array region and that includes a low-voltage transistor, which includes a gate electrode and a second gate insulating film thinner than the first gate insulating film below the gate electrode.