Disclosed is a semiconductor integrated circuit for a regulator for forming a low current consumption type DC power supply device. The semiconductor integrated circuit includes an output transistor, a control circuit, an operation control transistor and a soft start circuit. The output transistor is connected between an output terminal and a voltage input terminal to which a DC voltage is input. The control circuit controls the output transistor according to a feedback voltage of an output. The operation control transistor controls an operation state of the control circuit. The soft start circuit gradually changes a voltage applied to a control terminal of the operation control transistor and delays activation of the control circuit at a time of applying a power supply voltage to the voltage input terminal.