PURPOSE: A portable human detector is provided to obtain the exact direction for a living object of constant temperature by increasing the sensitivity of a differential infrared sensor. CONSTITUTION: A portable human detector is operated by the steps of; filtrating the infrared rays only in a range of 7-15 micrometers with a filter(12) from the infrared rays of a living object at a certain distance; detecting the change in the total amount of the infrared rays projected on an infrared sensor(10); recognizing the living object in front of a user by vibrating a vibrator directly or indirectly contacted to the human body of the user; and automatically radiating supersonic waves during a certain time in the detected direction through a supersonics wave oscillator. Therefore, the portable human detector is used to detect the human body and animals difficult to distinguish with the naked eye at night.
