A device and a method for continuous high-pressure treatment; the method, comprising the steps of increasing the pressure of raw materials (25) in a feed tank (9) by a pressurizing pump (1) so as to continuously feed the raw material to treatment containers (6) and (6a) and increasing the flow rate of the pressurizing pump (1) over that of a depressurizing pump (2) or continuously exhausting the raw material from the treatment containers (6) and (6a) through a pressure regulating flow path resistance (59) while depressurizing; the device, comprising pressure releasing bypass circuits (55) disposed in the flow path resistance (59) in parallel with each other, wherein the insides of the treatment containers (6) and (6a) are kept in a specified high-pressure state during the continuous processing.