printing inspection device that reads printing including a two-dimensional code printed on a printing target, the device comprising: means for inputting a recognition target including a two-dimensional code in a form of a multi-level image; image binarization means for binarizing the multi-level image with a predetermined binarization threshold value and outputting a binary image; two-dimensional code detection means for detecting a region of a two-dimensional code from the binary image; decoding means for decoding the two-dimensional code; and read test means for performing a read test, wherein the read test means performs a read test by binarizing one or more inspection samples with brightness values for all gradations, as a threshold value and obtains a maximum value and a minimum value of readable brightness values, characterized in that the read test means causes the obtained maximum value and minimum value to be displayed in a display portion, and sets a median value between the minimum value and the maximum value, as a binarization threshold value for a two-dimensional code image in a practical printing inspection, wherein when the read test is performed, an average brightness value for all pixels in a printing read region, and a difference between the calculated average brightness value and the median value is obtained as a correction value, in the practical printing inspection, the average brightness value for all pixels in the printing read region is calculated for each inspection target, and the multi-level image is binarized with a numerical value obtained by adding the correction value to the average brightness value, as the binarization threshold value. means for inputting a recognition target including a two-dimensional code in a form of a multi-level image; image binarization means for binarizing the multi-level image with a predetermined binarization threshold value and outputting a binary image; two-dimensional code detection means for detecting a region of a two-dimensional code from the binary image; decoding means for decoding the two-dimensional code; and read test means for performing a read test, wherein the read test means performs a read test by binarizing one or more inspection samples with brightness values for all gradations, as a threshold value and obtains a maximum value and a minimum value of readable brightness values, performs a read test by binarizing one or more inspection samples with brightness values for all gradations, as a threshold value and obtains a maximum value and a minimum value of readable brightness values, characterized in that the read test means causes the obtained maximum value and minimum value to be displayed in a display portion, and sets a median value between the minimum value and the maximum value, as a binarization threshold value for a two-dimensional code image in a practical printing inspection, causes the obtained maximum value and minimum value to be displayed in a display portion, and sets a median value between the minimum value and the maximum value, as a binarization threshold value for a two-dimensional code image in a practical printing inspection, wherein when the read test is performed, an average brightness value for all pixels in a printing read region, and a difference between the calculated average brightness value and the median value is obtained as a correction value, in the practical printing inspection, the average brightness value for all pixels in the printing read region is calculated for each inspection target, and the multi-level image is binarized with a numerical value obtained by adding the correction value to the average brightness value, as the binarization threshold value.