A hair holder (1) composed of two hair holding sheets (3) for holding a hair bundle in a prescribed shape. The hair holding sheet (3) is an agent-impregnated sheet (3a) having a Taber stiffness of 0.2 mN·m or higher and a water retention of 0.03 g/cm2 or more and impregnated with a hair treating agent. Two agent-impregnated sheets (3a) are joined together to make a flat tube (1A) having an opening at each end thereof and a hollow (12) through which a hair bundle is to be inserted.