1. A speech recognition apparatus comprising: means for receiving voice data; means for determining whether duration of a silence interval that follows an utterance part has reached a criterion time for determining completion of an utterance; means for suspending output of a speech recognition result when determined as not yet having reached; language model storage means for storing information concerning a language model; storage means for storing a recognition candidate word sequence changed on the basis of a speech recognition grammar, and information indicating whether a last word of a word sequence is a final word; recognition candidate extracting means for extracting a recognition candidate word sequence corresponding to the received voice data, on the basis of said language model; final word determination means for determining whether a word at an utterance last end is a final word, from the extracted recognition candidate word sequence; and recognition result output means for outputting a speech recognition result in a time shorter than said criterion time when the final word determination means has determined as being a final word, and outputting a speech recognition result in case that new voice data is not present within said criterion time when determined as not being a final word.