There is a jump in the number of devices formed on a single wafer, and it takes a lot of time to inspect a single wafer. Specifically, the organic semiconductor material has a 1,1\u2032:2\u2032,1\u2033:2\u2033,1\u2032\u2033quaterphenyl-4-4\u2032\u2033-diyl group, and one of the terminals of the 1,1\u2032:2\u2032,1\u2033:2\u2033,1\u2032\u2033quaterphenyl-4-4\u2032\u2033-diyl group is bonded to a skeleton having an electron-transporting property such as a benzoxazole group or an oxadiazole group. The method of this invention produces simplified electropherograms by reducing the number of signals that must be separated and subsequently measured, and therefore increases the accuracy of the detection andor quantification of target analyte concentration in a sample. Accordingly, the liquid tank can be mounted to a lower portion and can be formed to take an arbitrary shape suitable to a space for the tank by utilizing a flowability of the liquid, so that a capacity of the liquid tank can be increased.