An information terminal system

PURPOSE:To facilitate the specification of objective plant equipments and to realize a speedy and precises portable terminal operation in a portable terminal equipment used on the site in the monitoring of a plant. CONSTITUTION:The system is provided with an equipment map information storage device 106 holding position information of the constitution equipments 108 of the plant, a sensor 101 measuring the position direction of the portable terminal equipment 110 and an equipment judgement means 105 comparing the measured position direction of the terminal equipment with the content of the equipment map information storage device 106 and specifying the plant equipments 108 which is pointed by the portable terminal 110. One equipment can be specified among the multiple equipments only by pointing the portable terminal 110 to the equipment becoming an object, and the speedy and precise operation can be executed compared with a case when an equipment code is inputted to the terminal.