PROBLEM TO BE SOLVED: To provide an automobile bumper with an ultrasonic sensor having high sensitivity and a wide measurement range.SOLUTION: A bumper with an ultrasonic sensor is formed from: a porous columnar piezoelectric ceramic sintered body in which pores of an average diameter ranged from 1 to 100 μm are dispersed, of which the porosity is ranged from 5 to 50 vol%, the height is ranged from 10 to 30 mm and the ratio of height in the case where a diameter of a bottom face is defined as 1, is ranged from 1.5 to 5; and electrode layers added to top and bottom faces of the porous columnar piezoelectric ceramic sintered body. The bottom face side electrode layer of a piezoelectric vibrator in the ultrasonic sensor including the piezoelectric vibrator in which the porous columnar dielectric ceramic sintered body is polarized in a height direction, is fixed to an inner surface of the bumper of an automobile directly or via an acoustic matching layer. The inner surface of the bumper of the automobile is a
