An apparatus for classifying a plurality of logs recorded in a log file includes: a parsing unit that performs a parsing of the logs in the log file; a rule generating unit that generates a rule for a data classification based on a result of the parsing; a data classifying unit that performs the data classification, based on the rule generated, to classify the logs into a plurality of groups; a display unit that displays a result of the data classification; and a rule editing that edits the rules based on an instruction from a user.