An integrated circuit, in which the influence of parasitic capacitance between a semiconductor substrate and a resistor and between the semiconductor substrate and a capacitor can be inhibited, and a DC-DC converter provided with the integrated circuit. A shielding layer of an n-type semiconductor is formed between a p-type semiconductor substrate and a resistor formed thereon and between the semiconductor substrate and a capacitor formed thereon. A point BOOT is connected to the shielding layer, at which an electric potential changes in the same way as a change in the reference potential of a functional circuit carrying out a specified operation by using the resistor and the capacitor.