Semiconductor storage device and reading method thereof

A semiconductor storage device comprising:

• a first memory cell and a second memory cell connected in series;
• a first word line connected to the first memory cell;
• a second word line connected to the second memory cell;
• a bit line connected to the first and second memory cells connected in series;
• a sense amplifier including a sense node and a transistor connected between the sense node and the bit line;
• and
• a controller configured to execute a read operation including a first read and a second read,
• wherein in the read operation in which the first word line is selected, the controller
• applies a first read voltage to the second word line during the first read,
• discharges the sense node through the transistor while applying the first read voltage, and determines a read result of the second memory cell based on a voltage of the discharged sense node,
• applies a second read voltage to the first word line during the second read,
• discharges the sense node through the transistor for a first time period while applying the second read voltage, and determines a first read result of the first memory cell based on a voltage of the sense node discharged for the first time period,
• discharges the sense node through the transistor for a second time period different from the first time period, and determines a second read result of the first memory cell based on a voltage of the sense node discharged for the second time period, and
• based on a read result of the second memory cell, outputs read data based on the first read result or the second read result of the first memory cell to an external memory controller.