To provide a method and apparatus for inspecting foreign substances, capable of reducing erroneous detection or no detection of the foreign substances due to refraction or reflection of an irradiation light when inspecting opaque foreign substances mixed into a transparent container filled with a transparent liquid.

The method for inspecting the foreign substances mixed into a liquid based on an image obtained by imaging the container filled with the liquid includes the steps of imaging the container at predetermined light intensity Lx capable of detecting an area of the container to generate a container search image of a predetermined luminance level, generating a foreign detection image of the predetermined luminance level corresponding to the predetermined light intensity Ly (Lx Ly) capable of detecting the foreign substances existing inside the container, and processing the container search image and the foreign substance detection image to inspect the foreign substances in the container.