[Problem] To provide a device for generating water containing fine bubbles of ozone and a method for generating water containing fine bubbles of ozone that make it possible to easily and inexpensively generate water containing fine bubbles of oxygen containing ozone. [Solution] A device for generating water containing fine bubbles is provided with: a storage tank 10 for storing water; a water electrolysis-type ozone generation means 20 comprising a plurality of plate-shaped electrolysis elements 21 for subjecting water to electrolysis and generating ozone and a DC power supply device 26 that applies DC voltage to each of the electrolysis elements 21; and a vibration-applying means 30 comprising a vibrating element 31 for applying vibration to water stored in the storage tank 10 and an oscillation device 33 for applying an AC signal of a continuous wave to the vibrating element 31. The vibration-applying means 30 applies vibration having a strength equal to or greater than 8.56×1012[W/m2] to the water either while or after the water electrolysis-type ozone generation means 20 generates ozone by applying DC voltage to the electrolysis elements 21.