The present invention provides a jet stream generating device that can generate a jet stream having high velocity, that can generate a jet stream of liquid at high efficiency, that can adjust the flow rate of the jet stream and energy of the liquid, and that can adjust the jet stream time, using a simple configuration. The present invention is a jet stream generating device (100) configured to generate a jet stream of liquid, having: a cylindrical liquid chamber (160) such as a metal cylindrical member； a nozzle (165) configured to open an end part of the liquid chamber 160 and inject liquid F in the liquid chamber (160) to outside； a liquid supply path (140) configured to supply liquid F into the liquid chamber (160)； a laser beam irradiation part (21) configured to irradiate a pulse laser beam into the liquid chamber (160), and vaporize the liquid F in the liquid chamber (160)； and a laser device (2) (laser oscillator) configured to control laser beam intensity and laser beam pulse width independently. An inner surface of the liquid chamber (160) has a mirror plane for reflecting and guiding the pulse laser beam emitted from the laser beam irradiation part (21) to the end part of the liquid chamber (160), and an adjusting part (170) configured to adjust a distance between the nozzle (165) and the laser beam irradiation part (21) is included.
