A contact pad is provided. The contact pad may be a strip-shaped component and forms at least one opening. A circuit device is also provided. The circuit device has a circuit board, at least one contact pad as mentioned above, and a cable. The contact pad is mounted on the circuit board as a connecting spot. The cable has at least one wire. The wire is mounted on the contact pad and covers the opening of the contact pad. An interval is formed in the opening and between the circuit board and the wire. With such structure, a capacitance formed between the wire and the circuit board may be the smallest and the impedance value may be the largest. Besides, the capacitance value can be adjusted via changing the material inside the interval or an area of the contact pad or the opening.