Provided is a depth image generating apparatus. The depth image generating apparatus may include a filtering unit, a modulation unit, and a sensing unit. The filtering unit may band pass filter an infrared light of a first wavelength band among infrared lights received from an object. The modulation unit may modulate the infrared light of the first wavelength band to an infrared light of a second wavelength band. The sensing unit may generate an electrical signal by sensing the modulated infrared light of the second wavelength band.