A semiconductor memory having an electrically writable/erasable memory cell includes a first gate insulating layer made from a compound containing silicon and oxygen; a first charge-storage layer being in contact with the first gate insulating layer made from a silicon nitride film, a silicon oxynitride film, or an alumina film; a second insulating layer thicker than the first gate insulting layer; a second charge-storage layer being in contact with the second insulating layer; a third insulating layer thicker than the first gate insulating layer being in contact with the second charge-storage layer; and a control electrode upon the third insulating layer.