Abstract: An intention estimation unit extractor that extracts one or more intention estimation units each of which is a unit on which an estimation of the intention is to be performed from an inputted language, an intention estimator that estimates a partial intention of a part which constructs each of the extracted intention estimation units, an intention co-occurrence weight calculator that calculates an intention co-occurrence weight based on a relationship between partial intentions, and an intention sequence estimator that generates an intention sequence corresponding to the inputted language by using one or more partial intentions, and generates an intention estimation result corresponding to the inputted language by using both a score showing a likelihood of the generated intention sequence and an intention co-occurrence weight which the intention co-occurrence weight calculator calculates for the partial intentions which construct the generated intention sequence are disposed.