To provide an attachment for a concrete form, which facilitates mounting thereof, contributes to shortening of working hours and improvement of workability, and is economically advantageous because of recyclability thereof.

The attachment is an integrally molded structure made of a synthetic resin material or a metallic material, and set up by arranging a projection 2 for a dripping groove, on one surface of a substrate 1 formed like a long plate, along one longitudinal side of the substrate, and a projection 3 for chamfering, along the other longitudinal side of the substrate 1.