To provide a highly reliable crime prevention sensor capable of preventing false reports as much as possible and performing accurate detection.

The crime prevention sensor includes a microwave sensor 110 for transmitting microwaves toward a detection area, receiving reflected waves of the microwaves from an object present in the detection area, outputting distance information corresponding to the distance to the object, and outputting vertical angle information corresponding to the direction to the object; a means 120 for determining the presence of objects to be detected and determining the presence of the object to be detected in the detection area when the distance information lies within a prescribed distance range determined according to the both the vertical angle information and information on the height of a position of installation; and an alarm signal output control means 130 for performing control in such a way as to output alarm signals when it is determined by the means 120 for determining the presence of objects to be detected that the object to be detected is present.