Abstract: The array of the present invention has a plurality of double-stranded oligonucleotides immobilized on a metal substrate. Each of the double-stranded oligonucleotides includes a first single-stranded oligonucleotide and a second single-stranded oligonucleotide. The first and second single-stranded oligonucleotides are entirely or partially bonded together in a complementary manner to form said double-stranded oligonucleotide. Among the first and second single-stranded oligonucleotides, only the first single-stranded oligonucleotide is bonded on said substrate. The present invention also relates to a method for analyzing the interaction between the immobilized biomolecules and another biomolecule or an aggregate thereof by use of the array.