Use of a flux-cored wire for gas-shielded arc welding, the wire comprising a sheath and a flux that fills the sheath, wherein the wire is used for gas-shielded arc welding using, as a shielding gas, a gas that satisfies relationships of 0% ≤ [O 2] ≤ 5%, 0% ≤ [CO 2] ≤ 15%, and {[CO 2] + (3 × [O 2])} ≤ 15 and that contains Ar as the balance where [O 2] represents a volume fraction of oxygen and [CO 2] represents a volume fraction of carbon dioxide, the flux-cored wire includes As, Sb, Pb, or Bi in a total content of 0.0010% or less in terms of mass fraction with respect to the total mass of the wire, a composition of a slag component in the wire satisfies, in terms of mass fraction with respect to a total mass of the wire, TiO 2: 4.00% to 9.00%, SiO 2: 0.30% to 2.00%, ZrO 2: 1.50% to 3.00%, Al 2 O 3: 0.30% or less, and MgO: 0.50% or less, a composition of an alloy component contained in the sheath and the flux of the wire satisfies, in terms of mass fraction with respect to the total mass of the wire, C: 0.005% to 0.150%, Si: 0.05% to 1.50%, Mn: 0.20% to 3.00%, Cr: 15.00% to 35.00%, Ni: 5.00% to 25.00%, Mo: 5.00% or less, Nb: 2.00% or less, Ti: 1.00% or less, N: 1.00% or less, optionally further comprising S: 0.020% to 0.100%, and the balance: Fe and incidental impurities; and a relationship {(3 × [O 2]) + [CO 2] + (0.0085 × A 2) - (0.19 × A)} ≤ 20.0 is satisfied where [Cr] represents a mass fraction of the Cr and [Nb] represents a mass fraction of the Nb with respect to the total mass of the wire, and A = {[Cr] + (4.3 × [Nb])}. wherein the wire is used for gas-shielded arc welding using, as a shielding gas, a gas that satisfies relationships of 0% ≤ [O 2] ≤ 5%, 0% ≤ [CO 2] ≤ 15%, and {[CO 2] + (3 × [O 2])} ≤ 15 and that contains Ar as the balance where [O 2] represents a volume fraction of oxygen and [CO 2] represents a volume fraction of carbon dioxide, the flux-cored wire includes As, Sb, Pb, or Bi in a total content of 0.0010% or less in terms of mass fraction with respect to the total mass of the wire, a composition of a slag component in the wire satisfies, in terms of mass fraction with respect to a total mass of the wire, TiO 2: 4.00% to 9.00%, SiO 2: 0.30% to 2.00%, ZrO 2: 1.50% to 3.00%, Al 2 O 3: 0.30% or less, and MgO: 0.50% or less, a composition of an alloy component contained in the sheath and the flux of the wire satisfies, in terms of mass fraction with respect to the total mass of the wire, C: 0.005% to 0.150%, Si: 0.05% to 1.50%, Mn: 0.20% to 3.00%, Cr: 15.00% to 35.00%, Ni: 5.00% to 25.00%, Mo: 5.00% or less, Nb: 2.00% or less, Ti: 1.00% or less, N: 1.00% or less, optionally further comprising S: 0.020% to 0.100%, and the balance: Fe and incidental impurities; and a relationship {(3 × [O 2]) + [CO 2] + (0.0085 × A 2) - (0.19 × A)} ≤ 20.0 is satisfied where [Cr] represents a mass fraction of the Cr and [Nb] represents a mass fraction of the Nb with respect to the total mass of the wire, and A = {[Cr] + (4.3 × [Nb])}. TiO 2: 4.00% to 9.00%, SiO 2: 0.30% to 2.00%, ZrO 2: 1.50% to 3.00%, Al 2 O 3: 0.30% or less, and MgO: 0.50% or less, a composition of an alloy component contained in the sheath and the flux of the wire satisfies, in terms of mass fraction with respect to the total mass of the wire, C: 0.005% to 0.150%, Si: 0.05% to 1.50%, Mn: 0.20% to 3.00%, Cr: 15.00% to 35.00%, Ni: 5.00% to 25.00%, Mo: 5.00% or less, Nb: 2.00% or less, Ti: 1.00% or less, N: 1.00% or less, optionally further comprising S: 0.020% to 0.100%, and the balance: Fe and incidental impurities; and a relationship {(3 × [O 2]) + [CO 2] + (0.0085 × A 2) - (0.19 × A)} ≤ 20.0 is satisfied where [Cr] represents a mass fraction of the Cr and [Nb] represents a mass fraction of the Nb with respect to the total mass of the wire, and A = {[Cr] + (4.3 × [Nb])}. a relationship {(3 × [O 2]) + [CO 2] + (0.0085 × A 2) - (0.19 × A)} ≤ 20.0 is satisfied where [Cr] represents a mass fraction of the Cr and [Nb] represents a mass fraction of the Nb with respect to the total mass of the wire, and A = {[Cr] + (4.3 × [Nb])}.