A manual device for applying a coating on a substrate by means of a tape has an applicator endpiece assembled to a casing and projecting from the casing. The applicator endpiece extends along a longitudinal direction and a lateral direction. The applicator endpiece has an attachment portion for assembling it to the casing, an applicator portion for applying the coating on the substrate, and a stem extending along the longitudinal direction between the attachment portion and the applicator portion. The stem is elastically deformable in such a manner that the applicator portion is movable between a rest position and an application position. The stem is an iso-stress stem.