It has been conventionally difficult to make circuits operate faster. The present invention is a semiconductor storage device including a reference voltage circuit that supplies a reference voltage, and first and second memory circuits, that performs a read/write operation when one of the first and second memory circuits is selected, wherein the first and second memory circuits each include a plurality of memory cells, a plurality of bit line pairs, a precharge circuit that connects a reference voltage circuit to a plurality of bit lines, a sense amplifier circuit that amplifies, when making a selection, a plurality of bit line pairs and a pull-down circuit that lowers any one of the plurality of bit line pairs below the reference voltage, the pull-down circuit of the second memory circuit lowers the bit line pair for a read/write operation period during which the first and second memory circuits are selected or non-selected and the precharge circuits of the first and second memory circuits connect a plurality of bit line pairs to the reference voltage circuit respectively during a precharge period.