The invention aims to ensure the necessary gettering ability, improve the strength of the outer peripheral portion of a wafer and prevent the occurrence of slip dislocations. According to the invention, an epitaxial silicon wafer is provided with an epitaxial silicon film on the surface thereof and composed of COP regions in the nitrogen concentration of 1*10<12> to 10<13> atoms/cm<3>. During the evaluation of heat treatment, the density of BMD (oxygen precipitate) formed inside the silicon wafer 20 is 1*10<8> * 10<9> / cm <3> in the entire radial direction of the wafer. In addition, the average density of the BMD in the outer peripheral region 21 of the outermost circumferential direction of the silicon wafer 20 is lower than the average density of the BMD in the central region 22, and the deviation of the BMD density of the outer peripheral region 21 is 3 The residual oxygen concentration in the outer peripheral region 21 is 8 * 10 atoms / cm or more.