A hardness tester for measuring hardness of a sample by applying a predetermined test force to a surface of the sample with an indenter to form an indentation and measuring dimensions of the indentation, the hardness tester comprising: an indentation former configured to form the indentation in the surface of the sample by pressing the indenter against the surface of the sample; an image capture controller configured to control an image capturer to capture an image of the surface of the sample and obtain image data of the surface of the sample; characterized by: an indentation area extractor configured to determine an indentation area formed in the surface of the sample based on the image data of the surface of the sample obtained by the image capture controller, the indentation area extractor comprising: a reduced image generator configured to generate a reduced image by scaling down the image obtained from the image data of the surface of the sample at a scale ratio selected from a plurality of predetermined scale ratios; and a pattern matcher configured to perform pattern matching with respect to the reduced image generated by the reduced image generator, the pattern matcher further configured to determine the indentation area based on a plurality of degrees of correlation between each area of the reduced image and a model, wherein the model includes an indentation shape corresponding to the indenter and wherein the degree of correlation is calculated in all areas in the reduced image by raster scanning the reduced image with the model, and wherein the patter matcher is further configured to determine an area of the reduced image showing the maximum degree of correlation as the indentation area when a maximum degree of correlation among the calculated plurality of degrees of correlation is determined to be equal to or greater than a predetermined threshold value; and a hardness calculator configured to calculate the hardness of the sample based on the indentation area determined by the indentation area extractor. an indentation former configured to form the indentation in the surface of the sample by pressing the indenter against the surface of the sample; an image capture controller configured to control an image capturer to capture an image of the surface of the sample and obtain image data of the surface of the sample; characterized by: an indentation area extractor configured to determine an indentation area formed in the surface of the sample based on the image data of the surface of the sample obtained by the image capture controller, the indentation area extractor comprising: a reduced image generator configured to generate a reduced image by scaling down the image obtained from the image data of the surface of the sample at a scale ratio selected from a plurality of predetermined scale ratios; and a pattern matcher configured to perform pattern matching with respect to the reduced image generated by the reduced image generator, the pattern matcher further configured to determine the indentation area based on a plurality of degrees of correlation between each area of the reduced image and a model, wherein the model includes an indentation shape corresponding to the indenter and wherein the degree of correlation is calculated in all areas in the reduced image by raster scanning the reduced image with the model, and wherein the patter matcher is further configured to determine an area of the reduced image showing the maximum degree of correlation as the indentation area when a maximum degree of correlation among the calculated plurality of degrees of correlation is determined to be equal to or greater than a predetermined threshold value; and a reduced image generator configured to generate a reduced image by scaling down the image obtained from the image data of the surface of the sample at a scale ratio selected from a plurality of predetermined scale ratios; and a pattern matcher configured to perform pattern matching with respect to the reduced image generated by the reduced image generator, the pattern matcher further configured to determine the indentation area based on a plurality of degrees of correlation between each area of the reduced image and a model, wherein the model includes an indentation shape corresponding to the indenter and wherein the degree of correlation is calculated in all areas in the reduced image by raster scanning the reduced image with the model, and wherein the patter matcher is further configured to determine an area of the reduced image showing the maximum degree of correlation as the indentation area when a maximum degree of correlation among the calculated plurality of degrees of correlation is determined to be equal to or greater than a predetermined threshold value; and a hardness calculator configured to calculate the hardness of the sample based on the indentation area determined by the indentation area extractor.