The present invention provides an update detecting apparatus capable of properly extracting an important update. The update detecting apparatus includes a difference extracting unit, a morphological analyzing unit, and an update determining unit. The difference extracting unit extracts the difference between text data included in a server-side file and text data included in a cache file. The morphological analyzing unit divides the difference extracted by the difference extracting unit into words (morphemes) and generates a word group. The update determining unit determines that an update is performed in the server-side file when a word satisfying a predetermined condition is included in the word group generated by the morphological analyzing unit.