A semiconductor device includes a bit line; a data bus line corresponding to the bit line; a selection transistor that controls electrical connection between the bit line and the data bus line; a write amplifier that writes data to the bit line through the data bus; and a test circuit. The test circuit sets the bit line to a first potential during a test period regardless of an operation of the write amplifier, sets the data bus line to a second potential and then sets the data bus line in a floating state to detect transition of the data bus line from the second potential to the first potential, with the selection transistor being activated to electrically connect the bit line and the data bus line.