An object detection device equipped at a predetermined height includes a waveform obtaining portion obtaining a wave height value of a reflected wave, a reference value calculation portion calculating a wave height value of a wave reflected from a reference obstacle present at the predetermined height as reference value, a detection value calculation portion calculating a wave height value of a wave reflected from a detection object as detection value, a reference distance calculation portion calculating a reference distance between the reference obstacle and the distance measuring sensor, a detection distance calculation portion calculating a detection distance between the detection object and the distance measuring sensor, a correction portion correcting the reference value and the detection value, and a height calculation portion calculating a height of the detection object relative to the predetermined height according to a relative comparison result of the corrected reference value and the corrected detection value.