A velocimeter is disclosed that includes a plurality of photodetectors detecting scattered light in different directions, the light being emitted from a laser source and reflected on a moving object. The velocimeter includes an analog-to-digital conversion unit converting detection signals of the photodetectors, a velocity calculator calculating velocities of the moving object, an amplitude calculator calculating the amplitudes of the detection signals, a dropout detector detecting dropouts of the detection signals, a time keeper keeping detection times of the dropouts, a switching-time calculator calculating signal switching times, a storage memory storing the velocities, the amplitudes, and the signal switching times, and an output selector selecting one of the velocities stored in the storage memory based on the amplitudes and the signal switching times and outputting the selected velocity.