Provided is a method for manufacturing a surface treatment steel sheet for a battery case, comprising forming a semi-gloss nickel plating layer by electroplating on at least the surface of a steel sheet that constitutes the outer surface of a battery case, wherein the nickel plating layer is formed by performing a plating treatment under conditions satisfying expression (1) and expression (2). (1): T/D>=6.0. (2): X>=-0.5*T/D+4.5. (In expressions (1) and (2), T is the bath temperature (DEG C) of a plating bath used in the plating treatment (60<=T<=80), D is the electric current density (A/dm2)during the plating treatment (1<=D<=10), and X is the thickness ([mu]m) of the nickel plating layer to be formed (1.0<=X).