An input protection circuit (10, 20, and 30) includes: a first transistor (4) of a field-effect type coupled in series between an input terminal (3) and an electronic circuit (1), the input terminal (3) receiving an input voltage, the electronic circuit (1) receiving an input voltage (Vin), the first transistor (4) switching to an off-state in a case where the input voltage is higher than a positive power supply voltage (VDD) of the electronic circuit; a second transistor (5) of a field-effect type coupled in series between the first transistor and the electronic circuit, the second transistor switching to an off-state in a case where the input voltage is lower than the negative power supply voltage (VSS) of the electronic circuit; and a voltage control circuit (11, 24, and 34) configured to maintain gate-source voltages of the first transistor and the second transistor as voltages within a power supply voltage range of the electronic circuit based on the input voltage.
