A pump system, comprising: a vibration actuator which can be electromagnetically driven; a pair of sealed chambers connected to a suction port and a discharge port; movable walls for respectively changing volumes of the pair of sealed chambers; a housing containing the vibration actuator, the pair of sealed chambers and the movable walls therein; a cuff connected to the pair of sealed chambers through a tube connecting between the cuff and the discharge port and provided outside the housing, wherein the movable walls are displaced due to the drive of the vibration actuator to respectively supply fluid in the pair of sealed chambers into the cuff, characterized in that: the pressure in the cuff is detected based on a consumption current of the vibration actuator, and the vibration actuator includes a shaft portion provided in the housing, a movable body supported by the shaft portion so that the movable body can perform reciprocating rotation with respect to the housing, a pair of coil core portions (85, 86) fixed to one of the housing and the movable body, and magnets (83, 84) provided on another of the housing and the movable body so as to respectively face the coil core portions (85, 86), and the vibration actuator has a spring mass system structure for supporting the movable body, wherein the spring mass system structure is constituted of magnetic springs formed by magnetic force acting between the coil core portions (85, 86) and the magnets (83, 84) and fluid springs formed by elastic force of compressed fluid in the pair of sealed chambers, and a drive frequency of the vibration actuator is set so as to be in a range in which the consumption current monotonically changes as the pressure in the cuff increases. a vibration actuator which can be electromagnetically driven; a pair of sealed chambers connected to a suction port and a discharge port; movable walls for respectively changing volumes of the pair of sealed chambers; a housing containing the vibration actuator, the pair of sealed chambers and the movable walls therein; a cuff connected to the pair of sealed chambers through a tube connecting between the cuff and the discharge port and provided outside the housing, wherein the movable walls are displaced due to the drive of the vibration actuator to respectively supply fluid in the pair of sealed chambers into the cuff, the pressure in the cuff is detected based on a consumption current of the vibration actuator, and the vibration actuator includes a shaft portion provided in the housing, a movable body supported by the shaft portion so that the movable body can perform reciprocating rotation with respect to the housing, a pair of coil core portions (85, 86) fixed to one of the housing and the movable body, and magnets (83, 84) provided on another of the housing and the movable body so as to respectively face the coil core portions (85, 86), and the vibration actuator has a spring mass system structure for supporting the movable body, wherein the spring mass system structure is constituted of magnetic springs formed by magnetic force acting between the coil core portions (85, 86) and the magnets (83, 84) and fluid springs formed by elastic force of compressed fluid in the pair of sealed chambers, and a drive frequency of the vibration actuator is set so as to be in a range in which the consumption current monotonically changes as the pressure in the cuff increases.