A steel for welding consisting of, as steel components, by mass%, C: a content of 0.015% to 0.045%, Si: a content [Si] of 0.05% to 0.20%, Mn: a content [Mn] of 1.6% to 2.5%, Ni: a content [Ni] of 0.1 % to 1.0%, Ti: a content [Ti] of 0.005% to 0.015%, B: a content of 0.0003% to 0.0015%, N: a content of 0.002% to 0.006%, O: a content of 0.0015% to 0.0035%, P: a content limited to 0.008% or less, S: a content limited to 0.005% or less, Al: a content [Al] limited to 0.004% or less, Nb: a content [Nb] limited to 0.004% or less, Cu: a content [Cu] limited to 0.5% or less, V: a content limited to 0.02% or less, Cr: a content [Cr] limited to 0.1% or less, Mo: a content [Mo] limited to 0.05% or less, Ca: a content [Ca] limited to less than 0.0003%, Mg: a content [Mg] limited to less than 0.0003%, Sb: a content [Sb] limited to 0.005% or less, Sn: a content [Sn] limited to 0.005% or less, As: a content [As] limited to 0.005% or less, and REM: a content limited to 0.005% or less, and a balance consisting of Fe and unavoidable impurities, in which P CTOD in the following equation 1 is less than or equal to 0.065%, CeqH in the following equation 2 is less than or equal to 0.225%, FB in the following equation 3 is greater than or equal to 0.0003%, and Bp in the following equation 4 is 0.09% to 0.30%, wherein in a thickness center portion of a cross-section in a thickness direction, the number of oxide particles having an equivalent circle diameter of 2 μm or greater is less than or equal to 20 particles/mm 2 and the number of Ti oxides having an equivalent circle diameter of 0.05 μm to 0.5 μm is 1.0×10 3 particles/mm 2 to 1.0×10 5 particles/mm 2, wherein: P CTOD = C + Cu / 22 + Ni / 67 + V / 3 CeqH = C + Si / 4.16 + Mn / 14.9 + Cu / 12.9 + Ni / 105 + V / 1.82 FB = B − 0.77 × N − 0.29 × Ti − 2 × O − 0.89 × Al wherein if O ′ = O − 0.89 × Al ≤ 0, then O ′ = 0; if Ti ′ = Ti − 2 O ′ ≤ 0, then Ti ′ = 0, if N ′ = N − 0.29 × Ti ′ ≤ 0, then N ′ = 0, and if FB = B − 0.77 × N ′ ≤ 0, then FB = 0; and Bp = 884 × C × 1 − 0.3 × C 2 + 294 × FB C: a content of 0.015% to 0.045%, Si: a content [Si] of 0.05% to 0.20%, Mn: a content [Mn] of 1.6% to 2.5%, Ni: a content [Ni] of 0.1 % to 1.0%, Ti: a content [Ti] of 0.005% to 0.015%, B: a content of 0.0003% to 0.0015%, N: a content of 0.002% to 0.006%, O: a content of 0.0015% to 0.0035%, P: a content limited to 0.008% or less, S: a content limited to 0.005% or less, Al: a content [Al] limited to 0.004% or less, Nb: a content [Nb] limited to 0.004% or less, Cu: a content [Cu] limited to 0.5% or less, V: a content limited to 0.02% or less, Cr: a content [Cr] limited to 0.1% or less, Mo: a content [Mo] limited to 0.05% or less, Ca: a content [Ca] limited to less than 0.0003%, Mg: a content [Mg] limited to less than 0.0003%, Sb: a content [Sb] limited to 0.005% or less, Sn: a content [Sn] limited to 0.005% or less, As: a content [As] limited to 0.005% or less, and REM: a content limited to 0.005% or less, and a balance consisting of Fe and unavoidable impurities, in which P CTOD in the following equation 1 is less than or equal to 0.065%, CeqH in the following equation 2 is less than or equal to 0.225%, FB in the following equation 3 is greater than or equal to 0.0003%, and Bp in the following equation 4 is 0.09% to 0.30%, wherein in a thickness center portion of a cross-section in a thickness direction, the number of oxide particles having an equivalent circle diameter of 2 μm or greater is less than or equal to 20 particles/mm 2 and the number of Ti oxides having an equivalent circle diameter of 0.05 μm to 0.5 μm is 1.0×10 3 particles/mm 2 to 1.0×10 5 particles/mm 2, wherein: P CTOD = C + Cu / 22 + Ni / 67 + V / 3 CeqH = C + Si / 4.16 + Mn / 14.9 + Cu / 12.9 + Ni / 105 + V / 1.82 FB = B − 0.77 × N − 0.29 × Ti − 2 × O − 0.89 × Al wherein if O ′ = O − 0.89 × Al ≤ 0, then O ′ = 0; if Ti ′ = Ti − 2 O ′ ≤ 0, then Ti ′ = 0, if N ′ = N − 0.29 × Ti ′ ≤ 0, then N ′ = 0, and if FB = B − 0.77 × N ′ ≤ 0, then FB = 0; and Bp = 884 × C × 1 − 0.3 × C 2 + 294 × FB