There is disclosed a duplex stainless steel that contains, in mass percent, N of 0.05% to 0.25%, C of 0.02% or less, P of 0.02% or less, Si of 0.5% or less, Mn of 1.2% or less, Ni of 6.0% to 8.0%, Cr of 24.0% to 26.0%, Mo of 3.0% to 5.0%, W of 6.5% or less, and Ta of 0.2% to 0.5% with the remainder being Fe and inevitable impurities. This can suppress tantalum nitride formation.