An acquisition section acquires trace information including a plurality of log information having information on contents and types of log information based on message information of test signals transmitted to a communication terminal and a series of reply signals from the communication terminals, and provides clock time information at which the respective message information have been acquired. The trace information including the plurality of log information, is displayed in predetermined formats. An indication bar display section displays an indication bar on which the plurality of log information are arranged in a time series based on the clock time at which the respective message information have been acquired. A log sequence display section displays a predetermined number of log information as log sequences having time stamps based on the clock time information at which the respective log information have been acquired, so as to be associated with the indication bar.