Disclosed is a semiconductor storage device having a dual-port SRAM cell with a smaller area and low-current consumption and securing a good static noise margin. The semiconductor storage device includes a memory cell circuit constituting the dual port SRAM cell comprised of six transistors. When driving the first or second word line, a word line driver circuit lowers a high-level voltage which is to be output to the driven word line such that the high-level voltage is lower than a high-level voltage which is to be output to both of the first and second word lines when driving both the first and second word lines.