An inner-cabin side part of a hollow part of a protector with a sensor extends between a top end and an inner-cabin side end with an inner-cabin side apex closest to an interior of an automobile body. A distance is shorter between the inner-cabin side apex and the inner-cabin side end than between the top end and the inner-cabin side apex. An outer-cabin side part of the hollow part extends between the top end and an outer-cabin side end with an outer-cabin side apex closest to an exterior of the automobile body. A distance is shorter between the outer-cabin side apex and the outer-cabin side end than between the top end and the outer-cabin side apex. Thicknesses of an outer coat of the hollow part are increased toward the apexes from the top end, and are uniform between the apexes and the inner-cabin side end and the outer-cabin side end.