To establish a package inspection system which can work well without requiring stop of the inspection line and provide low-cost package inspecting devices.

A package inspection system includes the first package inspection line 1 consisting of a main package inspecting device 2 to automatically inspect the number of feathers in package, any contamination, unacceptable shape, etc., being the items capable of clearing ocularly, and an aux. package inspecting device 3 which inspects the weight and diameter of package not admitting ocular inspection and enables such inspection for the items given above through additional equipment of a light source and mirror as a low-cost facility. Even in case the main package inspecting device 2 can no more work for necessary inspection, it is possible to perform inspection with the aux. package inspecting device 3.