A sense amplifier includes a first transistor having a gate electrode electrically connected to a bit line and a first electrode electrically connected to a complementary bit line. A second transistor has a gate electrode electrically connected to the complementary bit line and a first electrode electrically connected to the bit line. An equalizing transistor is disposed between the gate electrode of the first transistor and the gate electrode of the second transistor. The first electrode of the first transistor and a first electrode of the equalizing transistor are electrically connected to each other, and the first electrode of the second transistor and a second electrode of the equalizing transistor are electrically connected to each other.