1. A method for inspecting a pattern comprising: acquiring, by an imaging apparatus, a plurality of images of an inspection target pattern, the images having edges and being acquired at different acquisition times; detecting the edges; matching corresponding ones of the detected edges; obtaining differences between the matched edges to generate difference vectors; predicting an edge shape of the inspection target pattern at an arbitrary future time, based on: the difference vectors; and intervals between the acquisition times; setting a threshold corresponding to a required specification of the inspection target pattern; and predicting a future time at which the inspection target pattern will fail to meet the required specification, based on the predicted edge shape and the threshold.