Abstract: A silicon wafer obtained by slicing a silicon single crystal ingot grown by the Czochralski method with or without nitrogen doping, wherein the silicon wafer has an NV-region, an NV-region containing an OSF ring region or an OSF ring region for its entire plane and has an interstitial oxygen concentration of 14 ppma or less, and a method for producing it, as well as a method for evaluating defect regions of a silicon wafer. Thus, there are provided a silicon wafer that stably provides oxygen precipitation regardless of position in crystal or device production process, and a method for producing it. Further, defect regions of a silicon wafer of which pulling conditions are unknown and thus of which defect regions are also unknown can be evaluated.