A semiconductor memory device includes a memory element, a first data line and a second data line, a first selection transistor, and a second selection transistor. The memory element includes a semiconductor element of MOS structure in which data is programmed when an insulating film provided in the semiconductor element is broken down by application of a voltage thereto. The first and second data lines are connected to a sense amplifier. The first selection transistor is configured to connect the memory element to the first data line in order to program data in the memory element. The second selection transistor is configured to connect the memory element to the second data line in order to program data in the memory element and detect the data programmed in the memory element. The second selection transistor has a smaller gate-electrode width smaller than the first selection transistor.