An electrolyzed water generation device comprising: an electrolytic chamber to which water to be electrolyzed is supplied; a first power feeder and a second power feeder disposed facing each other in the electrolytic chamber; and a membrane arranged between the first power feeder and the second power feeder and dividing the electrolytic chamber into a first polar chamber on a side of the first power feeder and a second polar chamber on a side of the second power feeder, characterized in that the electrolyzed water generation device further comprises: a first flow passage delivering electrolyzed water generated in one of the first polar chamber and the second polar chamber to a first water discharge port; a second flow passage delivering electrolyzed water generated in another one of the first polar chamber and the second polar chamber to a second water discharge port; a flow passage switching valve switching connections of the first polar chamber and the second polar chamber to the first flow passage and the second flow passage; a polarity switching unit that is configured to switch polarities of the first power feeder and the second power feeder; and a determination unit that is configured to determine switching timing of the polarity switching unit and the flow passage switching valve; and a water supply detection unit that is configured to detect water supply to the electrolytic chamber; wherein the determination unit is further configured to: - integrate electrolysis time in the electrolytic chamber; and - determine that the switching timing arrives when an integrated value of the electrolysis time reaches a predetermined threshold value without the polarities being switched and when a predetermined time passes without the water supply detection unit detecting water supply to the electrolytic chamber after the integrated value of the electrolysis time reaches the threshold value without the polarities being switched. an electrolytic chamber to which water to be electrolyzed is supplied; a first power feeder and a second power feeder disposed facing each other in the electrolytic chamber; and a membrane arranged between the first power feeder and the second power feeder and dividing the electrolytic chamber into a first polar chamber on a side of the first power feeder and a second polar chamber on a side of the second power feeder, characterized in that the electrolyzed water generation device further comprises: a first flow passage delivering electrolyzed water generated in one of the first polar chamber and the second polar chamber to a first water discharge port; a second flow passage delivering electrolyzed water generated in another one of the first polar chamber and the second polar chamber to a second water discharge port; a flow passage switching valve switching connections of the first polar chamber and the second polar chamber to the first flow passage and the second flow passage; a polarity switching unit that is configured to switch polarities of the first power feeder and the second power feeder; and a determination unit that is configured to determine switching timing of the polarity switching unit and the flow passage switching valve; and a first flow passage delivering electrolyzed water generated in one of the first polar chamber and the second polar chamber to a first water discharge port; a second flow passage delivering electrolyzed water generated in another one of the first polar chamber and the second polar chamber to a second water discharge port; a flow passage switching valve switching connections of the first polar chamber and the second polar chamber to the first flow passage and the second flow passage; a polarity switching unit that is configured to switch polarities of the first power feeder and the second power feeder; and a determination unit that is configured to determine switching timing of the polarity switching unit and the flow passage switching valve; and a water supply detection unit that is configured to detect water supply to the electrolytic chamber; wherein the determination unit is further configured to: - integrate electrolysis time in the electrolytic chamber; and - determine that the switching timing arrives when an integrated value of the electrolysis time reaches a predetermined threshold value without the polarities being switched and when a predetermined time passes without the water supply detection unit detecting water supply to the electrolytic chamber after the integrated value of the electrolysis time reaches the threshold value without the polarities being switched. - integrate electrolysis time in the electrolytic chamber; and - determine that the switching timing arrives when an integrated value of the electrolysis time reaches a predetermined threshold value without the polarities being switched and when a predetermined time passes without the water supply detection unit detecting water supply to the electrolytic chamber after the integrated value of the electrolysis time reaches the threshold value without the polarities being switched.