In a nonvolatile semiconductor memory which comprises a source region and a drain region formed on one surface of a semiconductor substrate having one conductivity type, a first insulating film formed on a channel region which is located between the source region and the drain region, a floating gate formed on at least a portion of the first insulating film and which is electrically floated, a control gate formed on the floating gate via a second insulating film, and high impurity concentration regions formed in or near a portion of the channel region and having the same conductivity type as that of the substrate, the floating gate is formed prior to the high impurity concentration regions, and the high impurity concentration regions are formed just outside the channel region by self-alignment with said floating gate using said floating gate as part of a mask.