Pump

A pump comprising:

• a first flat plate having one main surface and another main surface facing each other;
• a second flat plate having one main surface facing the one main surface of the first flat plate;
• a piezoelectric element arranged on the first flat plate;
• a side wall arranged on an outer side relative to outer edges of the first flat plate and the second flat plate;
• a first support member supporting the outer edge of the first flat plate and the side wall;
• a second support member supporting the outer edge of the second flat plate and the side wall;
• a first shielding plate arranged between the first flat plate and the second flat plate, facing the first flat plate and the second flat plate at the outer edges of the first flat plate and the second flat plate, having an opening at a center, and fixed to the side wall;
• a first ventilation hole provided between the outer edge of the first flat plate and the side wall;
• a second ventilation hole provided between the outer edge of the second flat plate and the side wall;
• a first valve body arranged in a region where the first flat plate and the first shielding plate face each other;
• and
• a second valve body arranged in a region where the second flat plate and the first shielding plate face each other,
• wherein a center side of one of the first valve body and the second valve body is fixed in a state in which an outer edge side of the one of the first valve body and the second valve body is movable, and an outer edge side of another one of the first valve body and the second valve body is fixed in a state in which a center side of the other one of the first valve body and the second valve body is movable.