A first voltage application circuit applies a first voltage determined to have a first voltage value to a first wiring connected to an asymmetrical memory cell. A second voltage application circuit applies a second voltage determined to have a second voltage value to a second wiring connected to the asymmetrical memory cell. When receiving a first input value from a first terminal, a voltage control circuit fixes the second voltage value and changes the first voltage value with a positive inclination with respect to the first input value within a range equal to or higher than the second voltage value. When receiving a second input value from a second terminal, the voltage control circuit fixes the first voltage value and changes the second voltage value with a negative inclination with respect to the second input value within a range equal to or lower than the first voltage value.