The present invention relates to a device and a method of detecting arbitrarily piled objects, and a device and a method for picking a detected object. The present invention may provide a device and a method of detecting an object, which extract a unique local characterized part of the object by using a visual sensor, detect an object region, and estimate a posture from the detected object region. Also the present invention may provide an object picking system capable of being applied to an actual production process, such as assembling or packaging, in a cell producing method.