Abstract: A lubricant composition capable of effectively preventing a rolling surface of a bearing from flaking owing to hydrogen embrittlement. The bearing is lubricated with the lubricant composition. The lubricant composition is lubricating oil or grease. The lubricant composition contains a molybdate. The lubricant composition also contains an organic acid salt. At least one molybdate is selected from sodium molybdate, potassium molybdate, and lithium molybdate. The organic acid salt is a sodium salt of an organic acid having one to 20 carbon atoms. 0.01 to 5 wt % of the molybdate is added to the entirety of the lubricant composition. 5 wt % to 70 wt % of the organic acid salt is added to the addition amount of the molybdate. The lubricant composition has a function of forming a film containing a molybdenum compound in addition to an iron oxide film on a worn surface of the bearing or on a fresh surface of an iron-based metal generated by wear.