To provide an accessory for a bottle with a bottle cap holding function that eliminates the need to find a place where a bottle cap is placed during driving of an automobile, and increases additional value of use.

The accessory for bottle has a holding piece part 3 having a holding hole 2 to be inserted into the neck part of a bottle body B from outside and a bag part 4 which is connected to the holding piece part 3 and into which a sales promotion article H is inserted. A pressure-sensitive adhesive part 5 where a bottle cap C opened and removed from the bottle body B is held stickily and which is formed by applying a pressure-sensitive adhesive is provided on a top surface of the bag part 4. The bag part 4 is formed of a thermoplastic plastic bag connected in one body along an outer side of the holding piece part 3, and the sales promotion article H is enclosed in the bag part 4.