A method for preparing original data of an odor image includes a measurement result acquiring step of acquiring each measurement result measured with respect to the odor substance included in the sample in each of a plurality of sensor elements of an odor sensor, and a data processing step of generating the original data for representing the odor of the sample in the image by processing each of the acquired measurement results. Each of the sensor elements has different detection properties with respect to the odor substance. In a case where each of the original data items is represented in a small image, the odor of the sample is represented in an odor image in a predetermined display mode in which small images are assembled, and each of the small images is varied in accordance with the magnitude of the value of each original data item.