The present invention suppresses the sliding between a circular plate-shaped member and a seating section, and improves the cleaning efficiency. A butterfly valve according to the present invention is provided with a circular plate-shaped valve element 2, a pair of support shafts 3 and 4, a pair of support shaft moving means, and a drive shaft 10. The valve element 2 is seated on and removed from the valve seat 14 from below. The drive shaft 10 drives and rotates the support shaft 3. As the support shafts 3 and 4 are rotated by the drive shaft 10, the valve element 2 is rotated and inverted. The support shaft moving means includes decentered shafts 5 and 6 that are rotatably supported by casings 1b and in which the support shafts 3 and 4 are respectively inserted in a decentered state, and air cylinders 7 and 8 configured to apply a force to the support shafts 3 and 4 in the upward and downward direction. When the valve element 2 is seated on or removed from the valve seat 14, the valve element 2 is moved in the upward and downward direction in a horizontal posture as the air cylinders 7 and 8 operate.