A method is for filling a fillable portion of a garment to be padded to obtain a padded garment, such as a garment or blanket. A cashmere fiber mass is fed towards a carding station. The cashmere fiber mass is mechanically opened and blended in the carding station by a carding machine to obtain a staple cashmere fiber. The staple cashmere fiber exiting from the carding station is fed towards a beating station. The staple cashmere fiber is cleaned in the beating station by cleaning air flow adapted to cross and inflate the staple cashmere fiber to remove residual impurities and dust from the staple cashmere fiber. The staple cashmere fiber exiting from the beating station is fed towards an injecting station and injected into the fillable portion by a pusher for introducing the staple cashmere fiber into the fillable portion to obtain the padded garment.