A typical form of apparatus for testing non-rotationally symmetrical hollow bodies for defects comprises a feed means for continuously conveying the hollow bodies into a test region of the apparatus, a means for conveying the hollow bodies through the test region of the apparatus, and a discharge means for conveying the hollow bodies out of the test region. Such an apparatus is used when there is a wish to check and inspect glass bodies of the above-indicated kind for surface defects such as for example cracks or irregular wall thicknesses in an automated procedure after production of the glass bodies, and to separate out glass bodies which are found to be defective.