The present invention provides an aptamer containing a sequence shown by the following formula (1) or formula (2): (1) GGGGCCUCC-N1-GGACYAAACC (2) GGGGCCUCC-N1-GGACWYAAACCwherein N1 shows 3 to 24 bases in length, Y is C or U, and W is A or U (uracil is optionally thymine), wherein the aptamer binds to a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5).