To provide a compact fluid controller by combining a valve with a limit switch.
A valve 6 has a projection part projecting from an opening of a casing 21, and has a piston 26 as a moving member linearly moving according to opening/closing of the valve 6 and brought into contact with the limit switch 7. The limit switch 7 faces the piston 26, and is installed so that the position thereof can be adjusted through a limit switch positioning means 8. The limit switch positioning means 8 has: a first bolt 42 fixed to a body 2; a second bolt 43 fixed to the limit switch 7; and a connection screw 44 connecting the bolts 42, 43. Pitches are different in the first bolt 42 and the second bolt 43.