The first region (RG1) contains a first organic material and a metal compound (a compound containing a metal element). The second region (RG2) contains the first organic material and the metal compound. The average intensity of the SIMS profile of the metal element in the second region (RG2) can be lower than the average intensity of the SIMS profile of the metal element in the first region (RG1). Specifically, the average intensity of the SIMS profile of the metal element in the second region (RG2) can be lower than 10%, preferably lower than 1.0%, of the average intensity of the SIMS profile of the metal element in the first region (RG1).