Abstract: A test structure of a semiconductor device with improved test reliability is provided. The test structure includes first and second active regions which are electrically isolated from each other and on which silicided first and second junction regions are formed, respectively, a semiconductor substrate or a well which is formed on lower parts of the first and second junction regions and has a conductivity type different from the first and second junction regions, and first and second pads through which an electrical signal is applied to the first and second junction regions and detected, and which are formed on the same level as a lower part of a metal layer or on the same level as the semiconductor substrate.