Provided are a heliostat calibration, device and a heliostat calibration method that can suppress time-change-dependent control error increases and can reduce calibration frequency. The present invention is provided with: an initial position information acquisition unit that acquires initial position information for a heliostat; a theoretical value calculating unit that calculates from the heliostat initial position information and sun position information a theoretical value that is related to the orientation of the heliostat; a deviation calculation unit that, using as input an actual measured value for the orientation of the heliostat, calculates the deviation between the theoretical value and the actual measured value at least two times a day; and a coordinate calibration unit that, when the deviation exceeds a threshold value, calibrates the coordinates of the heliostat such that the deviation is at or below the threshold value.