The adhesive compositions and the cover lay film and flexible copper-clad laminate using the same

It has good adhesion to an insulating film such as a polyimide film, and to provide an adhesive composition having excellent dielectric properties. A carboxyl group-containing styrene-based elastomer (A), an adhesive composition containing an epoxy resin (B), the content of the epoxy resin (B), the carboxyl group-containing styrene-based elastomer (A) 100 from 1 to 20 parts by mass per part by mass, and adhesive composition, characterized in that the dielectric constant of the cured adhesive was measured at a frequency 1GHz is less than 2.5.