NONVOLATILE SEMICONDUCTOR STORAGE DEVICE

摘要

A memory array (10) has disposed therein a plurality of memory cells (11) in matrix, each of said memory cells including a cell transistor (TC) and a variable resistance element (RR) connected to one end of the cell transistor (TC), and furthermore, the memory array is provided with a cell transistor performance measuring cell (12) having an MOS transistor (MTC). Readout characteristics and reliability characteristics of a nonvolatile semiconductor storage device are improved by stabilizing, using the cell transistor performance measuring cell (12), resistance values of the variable resistance element (RR) in a low resistance state and a high resistance state irrespective of fluctuation of the cell transistor (TC).