1 ) A speech recognition device configured to include a computer, the speech recognition device comprising: a storage area for storing a feature quantity acquired from a speech signal for each frame; storing portions for storing acoustic model data and language model data, respectively; an echo adaptation model generating portion for generating echo speech model data from a speech signal acquired prior to a speech signal to be processed at the current time point and using the echo speech model data to generate adapted acoustic model data; and recognition processing means for utilizing said feature quantity, said adapted acoustic model data and said language model data to provide a speech recognition result of the speech signal.