A fluid control device includes a piezoelectric actuator and a deformable substrate. The piezoelectric actuator includes a piezoelectric element and a vibration plate. The piezoelectric element is attached on a surface of the vibration plate. The piezoelectric element is subjected to deformation in response to an applied voltage. The vibration plate is subjected to a curvy vibration in response to the deformation of the piezoelectric element. The deformable substrate includes a flexible plate and a communication plate, which are stacked on each other. Consequently, a synchronously-deformed structure is defined by the flexible plate and the communication plate collaboratively. There is a specified depth between the flexible plate and the vibration plate. The flexible plate includes a movable part corresponding to the vibration plate.