An EEPROM having a nonvolatile memory cell is provided. The nonvolatile memory cell has: a first well formed in a substrate; a floating gate formed on the substrate through a gate insulating film to overlap a first region of the first well; first and second diffusion layers formed in the first well to contact the first region; and a MOS transistor whose gate electrode is the floating gate and through whose gate insulating film charges are transferred with respect to the floating gate. The first diffusion layer and the second diffusion layer are of opposite conductivity types.