A semiconductor storage device has a memory cell (501, 502) storing data; bit lines (BL1, BL2) connected to the memory cell, allowing therethrough data input or output to or from the memory cell; a sense amplifier (506a) connected to said bit lines, amplifying data on the bit lines; and a switching transistor (505a) connecting or disconnecting the bit line connected to the memory cell to or from the bit line connected to the sense amplifier. The switching transistor operates differently in a first memory cell access operation and in a second memory cell access operation.