A rolling bearing composed of a steel product, which contains alloying elements so as to satisfy the following chemical composition, in mass %, that C: 0.6 to 1.3 %, Si: 0.3 to 3.0 %, Mn: 0.2 to 1.5 %, P: 0.03 % or less, S: 0.03 % or less, Cr: 0.3 to 5.0 %, Ni: 0.1 to 3.0 %, Al: 0.050 % or less, Ti: 0.003 % or less, O: 0.0015 % or less, N: 0.015 % or less, and the balance: Fe and inevitable impurities, and has a nitrogen-rich layer, and austenite grains having a particle size number in a range exceeding No.10.