Abstract: There is provided a nonvolatile semiconductor memory which is capable of operating stably and performing high-speed access operation. A timing generation means 51 for generating timing signals which make a memory core unit 4 perform access operation uses first and second clocks of the same cycle and different phases. The timing generation means 51 generates timing signals for at least one first-half event among a plurality of read access events, according to the first clock, the phase of which precedes a phases of the second clock, and generates timing signals used for processing the remaining events, according to the second clock.