Knocking sensor

There is provided a knocking sensor that has good insulation characteristics even at an operating temperature of 150° C. or more and is excellent in the accuracy of knocking detection. The knocking sensor 10 includes a sensor body 20 including: a metal shell 12 that includes a cylindrical portion 12a and a flange portion 12b positioned at one end of the cylindrical portion 12a and protruding outward in a radial direction; an annular piezoelectric element 15; upper and lower electrode plates 16 and 14 that are superimposed on upper and lower surfaces of the piezoelectric element 15; a weight 17 that is disposed so that the piezoelectric element 15 is interposed between the weight and the flange portion 12b; a lower insulating plate 13 that is disposed between the flange portion 12b and the lower electrode plate 14; and an upper insulating plate 13t that is disposed between the upper electrode plate 16 and the weight 17; and a resin molding 11 that covers the sensor body 20. Further, the thickness of each of the upper and lower insulating plates 16 and 14 is in the range of 0.05 mm to 0.50 mm, and the resin molding 11 is made of polyphenylene sulfide having good heat resistance.