Abstract: A fluid control device is characterized in that the device is structured of a hollow first fluid path (21) and second fluid path (22), a housing portion (1) formed between the first fluid path and the second fluid path and having a hollow portion with a cross-sectional area larger than cross-sectional areas of both fluid paths, and a valve member (3) that has a main body (31) and a projection portion (32) that are installed in an opening portion where the first fluid path is connected to the hollow portion and that is formed of an elastic material. The fluid control device enables the circulation of liquid when the pressure of liquid flowing from the first fluid path toward the second fluid path is more than a predetermined level. The fluid control device enables accurate and safe measurement of pressure including blood pressure, and, when flushing operation of an infusion circuit etc.