PURPOSE: To provide a method for inspecting the foreign matter defect of the heel part of a bottle, which is suitable for automation in a bottle making or bottle filling factory line.

CONSTITUTION: A mechanism part 19 for introducing a bottle 6 from a manufacturing line which is a known bottle conveying means; a mechanism part 16 for rotating the bottle once or more; a mechanism part for returning the bottle onto the manufacturing line; and a lighting device 8 having a quantity of light sufficient to be transmitted by the heel part of the bottle from the oblique direction of the bottle are arranged. First and second mirror devices 28, 29 following the heel part of the bottle are arranged opposite to the lighting device 8 with the bottle between, and the first and second mirror device 28, 29 are arranged at an angle of about 30°-about 70° to horizontal surface and at an angle different therefrom, respectively. In the same part of the heel part of the bottle, only an image of foreign matter, or both the image of foreign matter and an image of shade generated by a thickness of the bottle or fluctuation of thickness are collected by two CCD cameras 21, 22 every mirror over the whole circumference of the bottle. The two images are subjected to logical sum operation, whereby the image of shade is erased to detect the presence of the foreign matter image, whereby the presence of foreign matter is judged.