Patent ID: 8836348

Claim:
An electrostatic capacitance type physical quantity sensor comprising: a detection element having a movable mass supported displaceably by a physical quantity given from the outside, and a detection electrode formed in at least one side of the movable mass; a capacitance detection circuit which detects a change in the capacitance of the detection electrode due to the displacement of the movable mass; and shield wirings which are disposed around wirings connected to an input of the capacitance detection circuit, the former wire being connected to a dc potential of low impedance, wherein the capacitance detection circuit converts the change in the capacitance of the detection electrode due to the displacement of the movable mass into an electric signal to thereby detect a physical quantity, and a value Cin of an input capacitance relative to a fixed potential of low impedance at a portion at which the detection element is connected with the capacitance detection circuit falls within a range of 1.5 pF<Cin<20 pF.