1. A semiconductor memory device comprising: a memory array including memory cells arranged in rows and columns; and a sense amplifier circuit wherein each of said memory cells comprising: at least one magnetoresistive element storing data; and an amplifying member used to amplify a signal generated by a current through said at least one magnetoresistive element, and wherein said sense amplifier circuit identifies data stored in said at least one magnetoresistive element in response to an output signal of said amplifying member.