A semiconductor device comprising an internal current generating section (1) for supplying an output current (i2) dependent on an input current (i1) into an IC, an external terminal (2) for connecting an external resistor (Rex) to the input end side of the internal current generating section (1), a current limiting element (3) connoted between the input end of the internal current generating section (1) and the external terminal (2), a first current limiting section (4) for pulling in the input current (i1) when one end voltage VA of the current limiting element (3) is higher than a first threshold voltage VB, and a second current limiting section (5) for pulling in the input current (i1) when the terminal voltage VC of the external terminal (2) is higher than a second threshold voltage. System down can be avoided by operating the internal circuit surely regardless of the state of the external terminal.