A composition for forming a passivation layer containing a compound expressed by general formula (I): M(OR1) m , and one material selected from the group consisting of a fatty acid amide, a polyalkylene glycol compound, and an organic filler. M includes at least one metallic element selected from the group consisting of Nb, Ta, V, Y and Hf; each R1 individually represents a C1-8 alkyl group or a C6-14 aryl group; and m represents an integer of 1 to 5.