1. A hardness tester for measuring hardness of a specimen by loading a predetermined testing force from an indenter on a surface of a specimen placed on a specimen stage to form an indentation, then measuring dimensions of the indentation, the hardness tester comprising: a focuser configured to focus on the surface of the specimen by changing a relative distance between a specimen stage and one of a first field lens and a second field lens having a magnification power less than the first field lens; an image capturer capturing an image of the surface of the specimen through one of the first field lens and the second field lens; a test position setter configured to set a test position at which the indentation is formed based on image information for the surface of the specimen captured by the image capturer through the second field lens; a focus position memory controller configured to measure a focus position through the first field lens at a predetermined test position among the test positions set by the test position setter, then associating the measured focus position with a test position within a predetermined range and storing the information in a memory; an indentation creator configured to form the indentation at the test position with the indenter; an image capture controller configured to obtain the focus position associated with the test position from the memory, displace the specimen based on the obtained focus position and the test position, and thereafter capture an image of the indentation formed by the indentation creator with the image capturer through the first field lens; and a measurer configured to measure the hardness of the specimen based on the indentation whose image has been captured by the control of the image capture controller.