1. An information processing apparatus, comprising: acquisition means for acquiring program information for broadcast contents; first extracting means for extracting keywords from the program information; counting means for counting the extracted keywords to obtain a keyword count; preserving means for preserving the keyword count; computing means for computing a difference value between a prior keyword count preserved in the preserving means and a current keyword count; second extracting means for extracting a predetermined keyword from the program information based on the difference value; and searching means for searching program information including the predetermined keyword extracted by the second extracting means.