To provide a power circuit capable of restraining the circuit scale by a soft start circuit.

A comparison part 11 of a power circuit 1 compares a reference voltage with an input voltage and outputs a voltage difference signal. An output voltage generating part 12 generates an output voltage based on a voltage difference signal and an input voltage generating part 14 generates an input voltage from an output voltage. A resistance element 16 generates a reference voltage from a reference current of a current output part 15. A capacitor 17 is connected to the resistance element 16 in parallel to be charged by the reference current. In such a power circuit, a current output part 15 reduces a reference current obtained at starting-up more than a reference current obtained during the operation.