A fluid control apparatus includes a piezoelectric pump and valve. The valve includes a second valve housing, second seal member, diaphragm, first seal member, and first valve housing and has a structure in which they are laminated in sequence. The first valve housing includes a second vent and third vent, has a valve seat, and includes six cavities. The second valve housing has a first vent and first vent and includes a valve seat and six first protrusions. The second valve housing further includes six second protrusions nearer the outer edges than the six first protrusions, as seen in the x-axis direction in plan view.