A method of making a steel sheet for a tension mask, including the steps of: hot rolling a steel consisting essentially of, by weight %, C: less than 0.1%, Si: 0.05% or less, Mn: 0.4 to 2%, P: 0.03% or less, S: 0.03% or less, sol.Al: 0.01% or less, N: 0.010% or more, and the balance of Fe; and annealing the cold rolled steel sheet, followed by a secondary cold rolling at a reduction rate of 35% or higher. The steel sheet produced by this method shows excellent creep resistance during blackening treatment and excellent magnetic shielding property with an anhysteretic permeability of 3400 or more at a DC bias magnetic field of 0.35 Oe, and therefore causes no color-deviation when applied to the tension mask.