DIFFUSION ESTIMATION METHOD AND DIFFUSION ESTIMATION DEVICE

PROBLEM TO BE SOLVED: To estimate concentration of diffusate with high accuracy.SOLUTION: A diffusion estimation device relating to the embodiment estimates concentration of a substance diffused in a prescribed area and includes: simulation means for outputting a plurality of concentration distributions in the prescribed area under each of a plurality of different conditions about the diffusion of the substance; correlation value calculation means for calculating correlation values about concentration between a target position and other positions in the prescribed area on the basis of the plurality of concentration distributions; actual measurement value acquisition means for acquiring an actual measurement value of the concentration of the substance from a sensor in the prescribed area; and concentration correction means for correcting the concentration at the target position on the basis of the correlation value between the position where the actual measurement value is acquired and the target position, and of the actual measurement value.