To provide a method for evaluating the degree of progress of fatigue due to white tissue separation in a rolling device.SOLUTION: A fatigue progress degree evaluation method is a method for evaluating the degree of progress of fatigue of a rolling device that includes two rolling members rolling in contact with each other, where at least one of the two rolling members is a steel rolling member. The fatigue progress degree is the degree of progress of fatigue of the rolling device due to white tissue separation occurring in the steel rolling member. A rolling fatigue part of the steel rolling member that is a part where rolling fatigue is caused due to the rolling contact has a white tissue and a black tissue, and the fatigue progress degree evaluation method evaluates the degree of progress of fatigue of the rolling device based on the amount of normal temperature non-diffusible hydrogen contained in the white tissue included in the rolling fatigue part.SELECTED DRAWING: Figure 1