Abstract: A monitor server 12 for monitoring a site used by Internet connection by a portable terminal and connected to the portable terminal through a portable packet network and a gateway is provided to adequately monitor the site. The monitor server 12 comprises an URL access activating processing section 54 for making an URL access to a site by controlling a portable terminal 16 through a portable packet network and a gateway at a predetermined timing, a service response monitoring processing section 56 and a service performance monitoring processing section 58 for obtaining response data that the portable terminal receives through the gateway and the portable packet network from the site, analyzing the response data, and detecting if any abnormality or trouble has occurred in the site, an alarm notification processing part 42 for generating alarm data for notifying of an abnormality or trouble, if occurred, and sending the data to another system.