PURPOSE: To obtain an apparatus which enables detection at high sensitivity of foreign matters in a liquid putted into a container being conveyed continuous ly without being affected by the foreign matters on the surface of the container.

CONSTITUTION: An inspector for foreign matters in a liquid is provided with a conveying path to convey a container 1 to be inspected continuously being turned, an image pickup means which lights the inside of the liquid from the bottom part of the container 1 provided in the conveying path to catch a plurality of image planes with a camera 3 at a fixed time interval from the side of the container 1, a memory to store the image planes and a judging means 9 which reads out an image plane to detect the foreign matters in the liquid being compared with the plurality of image planes. Then, a correction means 7 is provided to move the image planes by a moving value of the surface of the container 1 associated with the turning of the container during the fixed time interval and the image corrected is compared with the image plane after the fixed time interval to detect the foreign matters in the liquid.