Provided is a composition which has an excellent affinity with the surface of an adhesive agent and can achieve a high etching rate. The composition according to one embodiment comprises: a quaternary alkylammonium fluoride or a hydrate of a quaternary alkylammonium fluoride; and, as an aprotic solvent, (A) an N-substituted amide compound having no active hydrogen on a nitrogen atom, and (B) a dipropylene glycol dimethyl ether, wherein (B) the dipropylene glycol dimethyl ether has the percentage of a structural isomer represented by formula (1) of at least 50 mass % with respect to the total amount of (B) the dipropylene glycol dimethyl ether.