Separation device

A separation device, comprising:

• a casing including an object discharging port provided on a first direction side than an object feeding port into which an object is fed, the object discharging port being configured to discharge the object having been dehydrated, and a separated liquid discharging port provided on a second direction side opposite to the first direction than the object feeding port, the separated liquid discharging port being configured to discharge separated liquid;
• a screw shaft provided inside the casing and extending in an extending direction of the casing;
• a first screw blade extending spirally on an outer peripheral surface of the screw shaft, and having a surface directed to the second direction side that faces space into which the object is fed from the object feeding port in the casing;
• and
• a second screw blade extending spirally on the outer peripheral surface of the screw shaft such that a predetermined gap is formed with respect to the first screw blade in the extending direction of the screw shaft, and having a surface directed to the first direction side that faces space into which the object is fed from the object feeding port in the casing, wherein
• an end part of the first screw blade on the first direction side is placed on the first direction side than an end part of the second screw blade on the first direction side.