There is provided a semiconductor device capable of supplying an analog input signal higher than or equal to an operating power supply voltage. An electrostatic discharge protection circuit corresponding to the analog input signal is provided for an external terminal that is supplied with an analog input signal generated with a first power supply voltage. A voltage divider resistor divides the analog input signal passing through the electrostatic discharge protection circuit into a voltage corresponding to a second power supply voltage lower that the first power supply voltage. An input circuit operating on the second power supply voltage receives the analog input signal divided by the voltage divider resistor to form an internal analog signal. There are provided first and second unidirectional elements. The first unidirectional element passes current from the input circuit's input terminal to the second power supply voltage. The second unidirectional element passes current from a circuit ground potential to a first circuit's input terminal.