Abstract: An apparatus for inspecting a thickness or deteriorating situation of a coating layer formed on a surface of a container, which includes an inspecting light irradiating unit to irradiate an inspecting light to a container with a coating layer formed thereon, an image pickup unit to receive a reflected light or a transmission light of the inspecting light irradiated by the inspecting light irradiating unit and reflected from the container or passing through the container, and to convert the reflected light or the transmission light into an image pickup signal and to output same, and an determining unit to determine a thickness or a deteriorating situation of the coating layer formed on the container by inputting the image pickup signal outputted from the image pickup unit and comparing an image pickup data indicated by the image pickup signal with a prememorized standard data.