To provide a liquid flow generating device simple in construction, less in generation of pulsation, performing forward and reverse feed at symmetrical efficiency and inhibiting back flow of liquid at the time of stopping driving.

The liquid flow generating device comprises a cylinder 4 formed with a flow passage 3a in communication with a liquid circulation path 3 and a plurality of pistons 5a, 5b, ... 5f disposed side by side at proper distances for reciprocation in the cylinder 4 orthogonally to the flow passage 3a to change a volume in the flow passage, and generates a pressure difference in the flow passage 3 on opposite sides of the cylinder 4 by successively driving the respective pistons on conditions related to each other so that the liquid flows in a direction according to the pressure difference.