An electrolyzed water generation device is provided with a first flow passage delivering electrolyzed water generated in one of a first polar chamber and a second polar chamber of an electrolytic chamber, a second flow passage delivering electrolyzed water generated in the other one of the first polar chamber and the second polar chamber, a double autochange crossline valve in which a flow rate regulating valve 74 and a flow passage switching valve 85 are interlocked, a polarity switching unit 51 switching the polarities of a first power feeder 41 and a second power feeder 42, and a determination unit 52 determining switching timing of the polarity switching unit 51 and the flow passage switching valve 85. The determination unit 52 integrates electrolysis time in the electrolytic chamber 40 and determines that the switching timing arrives when an integrated electrolysis time t reaches a predetermined threshold value T without the polarity being switched.