An obstacle detection device (100) is provided with: a sonar (2) which transmits a sinusoidal search wave (SW); an obstacle detection unit (13) which detects the presence or absence of an obstacle (O) on the basis of a reflected wave (RW) received by the sonar (2); a distorted waveform generation unit (14) which generates a distorted waveform relative to the waveform of the reflected wave (RW); a harmonic extraction unit (15) which extracts a harmonic (H) relative to the reflected wave (RW), on the basis of the distorted waveform; and a type determination unit (16) which calculates an amount of Doppler shift on the basis of the harmonic (H) and thereby determines whether the obstacle (O) is a stationary object or a moving object. The obstacle detection device (100) outputs a signal representing the result of the detection by the obstacle detection unit (13) and the result of the determination by the type determination unit (16).