An environment measurement system that measures environmental conditions of a measurement object space, comprising: a plurality of mobile sensor terminals adapted to move in the measurement object space; each mobile sensor terminal including an environment measurement section, and a terminal control section, and a wireless positioning section, the environment measurement section adapted to measure environmental conditions neighboring the mobile sensor terminal, the terminal control section adapted to obtain measurement values measured by the environment measurement section and to exchange data with other mobile sensor terminals, and the wireless positioning section adapted to detect the position of the mobile sensor terminal by using wireless communication; the environment measurement system further comprising a preset measurement point list for measuring environmental conditions; wherein the plurality of mobile sensor terminals are adapted to detect the position of each other, by transmitting or receiving wireless communication signals, to measure environmental conditions while switching two roles: a position detection object terminal role for moving and position detection to move to a measurement point and a position detection standard terminal to designate a standard known position for position detection without moving; the environment measurement system being characterized in that the terminal control section 2210 is further adapted to: - calculate a distance between a position of a measurement point where measurement of environmental conditions has not been completed among the preset measurement point list and a current position of each mobile sensor terminal and make a measurement point in which at least three or more distances out of calculated distances are smaller than a predetermined value to be the next measurement point; and - decide the position detection object terminal and position detection standard terminal other than the same among each mobile sensor terminal based on the position of the next measurement point. a plurality of mobile sensor terminals adapted to move in the measurement object space; each mobile sensor terminal including an environment measurement section, and a terminal control section, and a wireless positioning section, the environment measurement section adapted to measure environmental conditions neighboring the mobile sensor terminal, the terminal control section adapted to obtain measurement values measured by the environment measurement section and to exchange data with other mobile sensor terminals, and the wireless positioning section adapted to detect the position of the mobile sensor terminal by using wireless communication; the environment measurement system further comprising a preset measurement point list for measuring environmental conditions; wherein the plurality of mobile sensor terminals are adapted to detect the position of each other, by transmitting or receiving wireless communication signals, to measure environmental conditions while switching two roles: a position detection object terminal role for moving and position detection to move to a measurement point and a position detection standard terminal to designate a standard known position for position detection without moving; the environment measurement system being characterized in that the terminal control section 2210 is further adapted to: - calculate a distance between a position of a measurement point where measurement of environmental conditions has not been completed among the preset measurement point list and a current position of each mobile sensor terminal and make a measurement point in which at least three or more distances out of calculated distances are smaller than a predetermined value to be the next measurement point; and - decide the position detection object terminal and position detection standard terminal other than the same among each mobile sensor terminal based on the position of the next measurement point. - calculate a distance between a position of a measurement point where measurement of environmental conditions has not been completed among the preset measurement point list and a current position of each mobile sensor terminal and make a measurement point in which at least three or more distances out of calculated distances are smaller than a predetermined value to be the next measurement point; and - decide the position detection object terminal and position detection standard terminal other than the same among each mobile sensor terminal based on the position of the next measurement point.