Provided is a knocking sensor having favorable insulation properties even at usage temperatures of 150 DEG C and higher, and having superior knocking detection precision. A knocking sensor (10) comprises a sensor body (20) and a resin molding (11) for covering the sensor body (20), the sensor body having a main metal fitting (12) including a tubular part (12a) and a flange part (12b) which projects toward the outside in the radial direction while also being positioned on one end of the tubular part (12a), an annular piezoelectric element (15), an upper electrode plate (16) and lower electrode plate (14) superimposed on the upper surface and lower surface of the piezoelectric element (15), a weight (17) sandwiching the piezoelectric element (15) with the flange part (12b), a lower insulating plate (13) disposed between the flange part (12b) and the lower electrode plate (14), and an upper insulating plate (13t) disposed between the upper electrode plate (16) and the weight (17). The thicknesses of the upper insulating plate (16) and the lower insulating plate (14) are within the range of 0.05-0.50 mm. The resin molding (11) is constituted of a polyphenylene sulfide having favorable heat resistance.