A detection method for detecting a plurality of different substances contained in a specimen using a label, includes sequentially the steps of flowing the specimen through a detecting element having a first substance trapping portion immobilizing a first substance trapping body, a second substance trapping portion immobilizing a second substance trapping body, and a channel, and flowing a solution containing the label through the first substance trapping portion immobilizing the first substance trapping body and the second substance trapping portion immobilizing the second substance trapping body. Additional steps include flowing a solution for generating a signal from the label through the first substance trapping portion immobilizing the label to thereby acquire a signal from, and flowing a solution for generating a signal from the label through the second substance trapping portion immobilizing the label to thereby acquire a signal.