A steel for nitrocarburizing, comprising: a chemical composition containing, in mass%, C: 0.02 % or more and less than 0.15 %, Si: 0.30 % or less, Mn: 1.5 % or more and 2.5 % or less, P: 0.025 % or less, S: 0.06 % or less, Cr: 0.5 % or more and 2.0 % or less, Mo: 0.005 % or more and 0.2 % or less, V: 0.02 % or more and 0.20 % or less, Nb: 0.003 % or more and 0.20 % or less, Al: more than 0.020 % and 1.0 % or less, Ti: 0.0070 % or more and 0.015 % or less, N: 0.0200 % or less, and Sb: 0.0030 % or more and 0.010 % or less, and optionally one or more selected from the group consisting of B: 0.010 % or less, Cu: 0.30 % or less, Ni: 0.30 % or less, Co: 0.2 % or less, Zr: 0.2 % or less, Hf: 0.3 % or less, Ta: 0.3 % or less, W: 0.4 % or less, Pb: 0.2 % or less, Bi: 0.2 % or less, Zn: 0.3 % or less, and Sn: 0.3 % or less, with a balance being Fe and inevitable impurities, satisfying any of the following Expressions and: in the case where the C content is 0.02 % or more and 0.10 % or less, 1.4 ≤ A ≤ 3.2 where A = 1000 × {7 × (Ti/48) + 17 × (Sb/122)}; and in the case where the C content is more than 0.10 % and less than 0.15 %, 0.9 ≤ A ≤ 2.3 where A = 850 × {5 × (Ti/48) + 13 × (Sb/122)}; and a steel microstructure in which an area ratio of bainite phase is more than 50 %, a prior austenite grain size is 100 μm or less, 300 or more Ti precipitates with an equivalent circular particle size of 30 nm or less disperse per μm 2, and segregated Sb exists in prior austenite grain boundaries, wherein the area ratio of bainite phase, the prior austenite grain size, the amount of Ti precipitates and the existence of segregated Sb are determined in accordance with the specifics given in the description. a chemical composition containing, in mass%, C: 0.02 % or more and less than 0.15 %, Si: 0.30 % or less, Mn: 1.5 % or more and 2.5 % or less, P: 0.025 % or less, S: 0.06 % or less, Cr: 0.5 % or more and 2.0 % or less, Mo: 0.005 % or more and 0.2 % or less, V: 0.02 % or more and 0.20 % or less, Nb: 0.003 % or more and 0.20 % or less, Al: more than 0.020 % and 1.0 % or less, Ti: 0.0070 % or more and 0.015 % or less, N: 0.0200 % or less, and Sb: 0.0030 % or more and 0.010 % or less, and optionally one or more selected from the group consisting of B: 0.010 % or less, Cu: 0.30 % or less, Ni: 0.30 % or less, Co: 0.2 % or less, Zr: 0.2 % or less, Hf: 0.3 % or less, Ta: 0.3 % or less, W: 0.4 % or less, Pb: 0.2 % or less, Bi: 0.2 % or less, Zn: 0.3 % or less, and Sn: 0.3 % or less, with a balance being Fe and inevitable impurities, satisfying any of the following Expressions and: in the case where the C content is 0.02 % or more and 0.10 % or less, 1.4 ≤ A ≤ 3.2 where A = 1000 × {7 × (Ti/48) + 17 × (Sb/122)}; and in the case where the C content is more than 0.10 % and less than 0.15 %, 0.9 ≤ A ≤ 2.3 where A = 850 × {5 × (Ti/48) + 13 × (Sb/122)}; and a steel microstructure in which an area ratio of bainite phase is more than 50 %, a prior austenite grain size is 100 μm or less, 300 or more Ti precipitates with an equivalent circular particle size of 30 nm or less disperse per μm 2, and segregated Sb exists in prior austenite grain boundaries, wherein the area ratio of bainite phase, the prior austenite grain size, the amount of Ti precipitates and the existence of segregated Sb are determined in accordance with the specifics given in the description. in the case where the C content is 0.02 % or more and 0.10 % or less, 1.4 ≤ A ≤ 3.2 where A = 1000 × {7 × (Ti/48) + 17 × (Sb/122)}; and in the case where the C content is more than 0.10 % and less than 0.15 %, 0.9 ≤ A ≤ 2.3 where A = 850 × {5 × (Ti/48) + 13 × (Sb/122)}; and a steel microstructure in which an area ratio of bainite phase is more than 50 %, a prior austenite grain size is 100 μm or less, 300 or more Ti precipitates with an equivalent circular particle size of 30 nm or less disperse per μm 2, and segregated Sb exists in prior austenite grain boundaries, wherein the area ratio of bainite phase, the prior austenite grain size, the amount of Ti precipitates and the existence of segregated Sb are determined in accordance with the specifics given in the description.