1. A word identification method comprising: a character recognition processing step of performing recognition processing of an input character string that corresponds to a word to be recognized by each character, thereby obtaining the character recognition result; a probability calculation step of obtaining a probability at which characteristics obtained as the character recognition result are generated by said character recognition processing by conditioning characters of words contained in a word dictionary that stores in advance a candidate of the word to be recognized; a first computation step of performing a predetermined computation between a probability obtained by this probability calculation step and the characteristics obtained as the character recognition result by said character recognition processing step; a second computation step of performing a predetermined second computation between the computation results obtained by said first computation relevant to the characteristics of the words contained in said word dictionary; and a word recognition processing step of obtaining the recognition result of said word based on the second computation result by this second computation step.