A semiconductor integrated circuit for a regulator, including: a control transistor; a control circuit; and a discharge circuit, wherein the discharge circuit includes: a constant current source circuit; a reference voltage generating circuit; a voltage comparator circuit; and a current amplification circuit, and wherein the control circuit is configured to control the control transistor in response to the control signal, and the discharge circuit is configured to operate the discharge transistor by the amplified current amplified by the current amplification circuit.