It is possible to achieve high analysis accuracy on the whole irrespective of a coverage ratio of a morpheme dictionary. A morpheme prediction section 38 outputs a morpheme label string as a morphological analysis result of input text by inputting a resultant vector generated for each character by a vector combination section 36 into a series predictor and sequentially performing calculation. At this point, there is used the series predictor which is subjected to learning in advance such that a morpheme label string obtained by inputting a resultant vector in which a character vector and a morpheme information vector are combined and which is generated without being combined with the morpheme information vector with a specific probability into the series predictor and sequentially performing the calculation coincides with a morpheme label string of learning data.