The present invention provides a tool for measuring the cleanliness of the interior of an endoscope channel, wherein the tool is for efficiently, rapidly, and reliably examining whether or not an endoscope is clean after being cleaned and sterilized. The tool for measuring the cleanliness of the interior of an endoscope channel is characterized in that a wiping cloth containing ultrafine fibers is attached to the tip of a filament having a thickness enabling the filament to be inserted into the endoscope channel.