1. An information extracting server comprising: a collecting unit configured to collect a text in which a keyword of interest indicating information of interest that a user is interested in appears, the keyword of interest, and a time of creation of the text; a keyword extracting unit configured to extract a keyword included in the text except for the keyword of interest, and the time of creation; a local hot word extracting unit configured to extract the keyword having a time score obtained on the basis of an appearance frequency of the keyword in a time interval, which is a period T1 backward from the time of creation, exceeding a first threshold value and a local score on the basis of the appearance frequency of the keyword in a local area indicating a range of a specific topic exceeding a second threshold value as a local hot word, and also extract the extracted time interval of the extracted keyword and the keyword of interest corresponding to the keyword; and a local hot word storing unit configured to store the extracted local hot word, the time interval, and the keyword of interest.