A screw type separation device includes: a casing that has a separated liquid discharge port on one end part side and has an object discharge port on the other end part side, while the other end part side is positioned lower, in terms of vertical directions, than the one end part side; a screw shaft provided inside the casing; a first screw blade; and a second screw blade that forms a first space between one face and the first screw blade facing the one face and forms a second space between the other face and the first screw blade facing the other face.