An illustration (a) of FIG. 13 is a graph showing a result of the analysis of the analysis EL layer 24T according to the embodiment. The analysis is carried out with the TOF-SIMS analyzer 41. An illustration (b) of FIG. 13 is a graph showing a result of the analysis of the analysis EL layer 94T according to the comparative example. The analysis is carried out with the TOR-SIMS analyzer 41.

As seen in an area “B” of the illustration (b) of FIG. 13, the result of the analysis of the analysis EL layer 94T according to the comparative example shows that, because of the influence of the charges to be accumulated on the surface of the analysis EL layer 94T by the treatments with the sputter gun 42 and the primary ion gun 43, the profile of the intensity signal according to the mass separation is disturbed after a sputtering time of 100 seconds has passed. Hence, the resulting profile is inappropriate.

In contrast, as seen in the illustration (a) of FIG. 13, the result of the analysis of the analysis EL layer 241 according to the this embodiment shows that, when the charges are accumulated on the surface of the analysis EL layer 24T by the treatments with the sputter gun 42 and the primary ion gun 43, the accumulated charges are dissipated through the second metal film 251, the first metal film 22T, and the ground wire. Hence, the profile of the intensity signal according to the mass separation is not disturbed, and the resulting profile is appropriate.