A semiconductor integrated circuit device has an internal circuit connected to each of an external terminal, a high-potential power source terminal, and a low-potential power source terminal, a surge protection circuit connected between the external terminal and the low-potential power source terminal to protect the internal circuit from a surge voltage applied to the external terminal, a capacitor having one terminal connected to the external terminal, a transistor connected between the other terminal of the capacitor and the low-potential power source terminal, and a control circuit which brings the internal circuit into a stopped state and does not activate the transistor when the surge voltage is applied to the external terminal.