An evaluation aid which can be used as a phantom (imitation lesion) when a digital X-ray image thereof is taken and then evaluation is carried out through the digital X-ray image. The evaluation aid is adapted to be used for taking a digital X-ray image thereof through which evaluation is carried out, and contains a substrate (plate-like body) including a plurality of regions having different X-ray absorption ratios and step members provided on the plate-like body.
