A screening measurement technology enabling a prompt determination about whether or not further confirmation is required by another measuring method, for an environmental sample, such as a sample containing dioxins, is provided. A sample solution in which a known amount of antibodies are mixed, is poured into a measurement cell (101) where an antigen derivative (107) that acquires antibodies of a subject substance comprising an antigen, is arranged in a flow channel (106) for the sample solution; whether or not a measurement result is within a pre-determined range including a reference value of the subject substance is determined based upon time-series signals of the measurement result; and the measurement result is transmitted.