1. A method for searching for a related term having rapidly increasing popularity, the method comprising: analyzing a search log and extracting a daily search frequency for search terms in the search log; comparing peaks of the daily search frequency extracted for the search terms in a period; analyzing relevance between candidate search terms for which the peaks have occurred together in the period with at least one of the search terms as a result of the comparison, and filtering out a candidate search term of the candidate search terms having no relevance; and wherein the extracting of the daily search frequency for search terms in the search log includes, extracting the daily search frequency for the search terms in the period, analyzing the daily search frequency for the search terms, extracting at least one search term having a search frequency that increases more rapidly than an increase reference value and decreases more rapidly than a decrease reference value, and extracting time information when a peak of the at least one search term has occurred.