To provide a pressure machine having a vibration suppressing device capable of securely lowering pressure pulsation and the resulting noise by a device of small and simple structure and also lowering pressure pulsation and noise without accompanying any special part replacement for an existing pump (pressure machine).

This pressure machine having the vibration suppressing device capable of suppressing vibration occurring on a casing by the operation of a moving body stored in the casing comprises a vibration detector detecting the vibration of the casing, a controller having an analyzing means analyzing a vibration mode in a prescribed time based on the detected vibration values of the casing and an offset vibration mode calculation means calculating the reverse phase vibration mode of the vibration mode canceling the vibration of the detected vibration values based on the results of the vibration analysis by the analyzing means, and a reverse phase excitation means suppressing the vibration of the casing by exciting the casing by the reverse phase vibration mode from the controller.