PURPOSE: To enable a pyroelectric sensor type traveling direction detection device to be improved.

CONSTITUTION: A traveling direction detection device is provided with a detection means with a pair of pyroelectric elements 12A and 12B where a light- reception visual field is set separately along a traveling direction of a body to be detected, a pair of wind comparators which compare each output of a pair of pyroelectric elements with a low-level first reference value and a high- level second reference value, and a discrimination means for discriminating a traveling direction of the body to be detected based on an order of output of a pair of wind comparators. where it is desirable that a pair of pyroelectric elements are connected mutually and inversely in series and it is so constituted that light from the body to be detected may not enter one polarity portion of a pair of pyroelectric elements and then a proper grounding is achieved.