A semiconductor storage device provided can increase a write margin and suppress increase of a chip area. The semiconductor storage device includes plural memory cells arranged in a matrix; plural bit-line pairs arranged corresponding to each column of the memory cells; a write driver circuit which transmits data to a bit-line pair of a selected column according to write data; and a write assist circuit which drives a bit line on a low potential side of the bit-line pair of a selected column to a negative voltage level. The write assist circuit includes first signal wiring; a first driver circuit which drives the first signal wiring according to a control signal; and second signal wiring which is coupled to the bit line on the low-potential side and generates a negative voltage by the driving of the first driver circuit, based on inter-wire coupling capacitance with the first signal wiring.
