The measurement accuracy of the wind speed at a long distance is improved without lowering a wind speed measurement rate at a short distance. A wind measurement lidar device 1 includes: a beam switching unit 8 to switch to another beam direction when beam selection time elapses in one beam direction, the beam selection time being time in which pulses of greater than or equal to a predetermined minimum number of pulses are generated; an integrated spectrum storage unit 12d to store an integrated spectrum obtained by integrating spectra for each of wind speed measurement sections being a combination of a beam direction and a time interval; spectrum integrating units 12c, 12e to generate an integrated spectrum by integrating, for each of the wind speed measurement sections, a plurality of spectra obtained from a plurality of the pulses transmitted in succession in a beam direction and an integrated spectrum being stored in the integrated spectrum storage unit; a wind speed calculating unit 12h to calculate the wind speed when the SN ratio of the integrated spectrum is greater than or equal to a first threshold value; and a stored integrated spectrum correcting unit 12j to store an integrated spectrum integrated for one of the wind speed measurement sections, for which no wind speed is calculated, into the integrated spectrum storage unit 12d.