An x-ray radiography system (XRS) equipped with a multiwalled carbon nanotube cathode was developed. This system has ordinary scanning electron microscopy (SEM) functions available for the precise adjustment of focusing conditions including astigmatism and alignment of an electron beam. The electron beam diameter on a target, which is one factor that limits spatial resolution of XRS, was estimated as 50 nm from the resolution of SEM images obtained. X-ray images were taken as a demonstration of the XRS, and clear images with resolution higher than 700 nm were successfully obtained. (C) 2008 American Vacuum Society.