An output end and an inverted output end of a latch circuit that is connected to an output buffer circuit are switched with each other, and thereby, the relationship between the data of “0” or “1” and the drain of a memory cell is connected or not connected to a bit line is changed. In addition, an input of a sense amplifier is fixed at the grounding potential by means of a test control signal, and thereby, positive logic is confirmed in the case where the output of the output buffer circuit is “L,” and negative logic is confirmed in the case where the output of the output buffer circuit is “H.”