An adhesive agent composition includes: a block copolymer (X) formed from a block (A) and a block (B), the block (A) having a glass transition point of 75 DEG C or higher, the block (A) containing a monomer unit having a first annular structure and a carboxyl group-containing monomer unit, and the block (B) containing an acrylic acid ester unit represented by the following general formula (1) in an amount of 70 mass% or more; and a tackifier (Y) having a softening point of 120 DEG C or more, the tackifier (Y) having a second annular structure, in which the mass ratio of the block (A) and the block (B) (block (A)/block (B)) is 10/90 to 40/60, the acid value derived from the block (A) in the block copolymer (X) is 8 mgKOH/g or more, at least one terminal of the block copolymer (X) is the block (A), and the amount of the tackifier (Y) is 5 to 40 wt% with respect to the amount of the block copolymer (X) of 100 mass %. The general formula (1) is CH2=CR1-COOR2, R1 being a hydrogen atom, and R2 being an alkyl group or an alkoxyalkyl group of straight chain having 8 or less carbon atoms.