Provided are a method for removing scale and a scale remover that can efficiently remove scale deposited inside a boiler can or the like in an addition amount of chemicals permissible in terms of cost without corroding a boiler, particularly can efficiently remove scale deposited inside a boiler can even in a facility operated with feed water containing high-concentration iron. A method for removing scale deposited in a system of a steam generating facility, wherein polyacrylic acid having a weight-average molecular weight of more than 20,000 and 170,000 or less and/or a salt thereof is added to feed water of the steam generating facility. When the feed water contains iron, polymethacrylic acid having a weight-average molecular weight of more than 1,000 and 100,000 or less and/or a salt thereof is further added in combination.