In this research, we use an organic thin-film that having 18-crown-6 ether as a sensitive material. The reasons of choosing the 18-crown-6 ether as a sensitive material because 2,4,6-TRINITROTOLUENE (TNT) is made from a nitroaromatic compound which is a hydrocarbon with unsaturated characteristics because a number of electrons is 4n + 2 when n = 1, 2, 3, and these electrons are not fixed. For this reason, the researcher will selected the 18-crown-6 ether because