A double-row self-aligning roller bearing comprising: an inner ring ; an outer ring having a raceway surface formed in a spherical shape; rollers interposed between the inner ring and the outer ring in two rows aligned in an axial direction, each of the rollers having an outer circumference formed in a spherical shape along the raceway surface of the outer ring ; and a hard film comprising: a foundation layer formed directly on a surface of at least one bearing component selected from among the inner ring , the outer ring , and the rollers ; a mixed layer formed on the foundation layer and mainly formed of tungsten carbide and diamond-like carbon; and a surface layer formed on the mixed layer and mainly formed of diamond-like carbon, wherein: the double-row self-aligning roller bearing is configured to be used such that the hard film is brought into sliding contact or into rolling and sliding contact with other bearing component in a boundary lubrication state; and the mixed layer is formed such that a content rate of the tungsten carbide in the mixed layer is continuously or stepwise decreased and a content rate of the diamond-like carbon is continuously or stepwise increased from a side of the foundation layer toward a side of the surface layer ; characterised in that the inner ring , the outer ring , and the rollers are formed of iron-based material; and the content of the hydrogen in the mixed layer is less than 10 atom%. an inner ring ; an outer ring having a raceway surface formed in a spherical shape; rollers interposed between the inner ring and the outer ring in two rows aligned in an axial direction, each of the rollers having an outer circumference formed in a spherical shape along the raceway surface of the outer ring ; and a hard film comprising: a foundation layer formed directly on a surface of at least one bearing component selected from among the inner ring , the outer ring , and the rollers ; a mixed layer formed on the foundation layer and mainly formed of tungsten carbide and diamond-like carbon; and a surface layer formed on the mixed layer and mainly formed of diamond-like carbon, wherein: the double-row self-aligning roller bearing is configured to be used such that the hard film is brought into sliding contact or into rolling and sliding contact with other bearing component in a boundary lubrication state; and the mixed layer is formed such that a content rate of the tungsten carbide in the mixed layer is continuously or stepwise decreased and a content rate of the diamond-like carbon is continuously or stepwise increased from a side of the foundation layer toward a side of the surface layer ; characterised in that the inner ring , the outer ring , and the rollers are formed of iron-based material; and the content of the hydrogen in the mixed layer is less than 10 atom%. the double-row self-aligning roller bearing is configured to be used such that the hard film is brought into sliding contact or into rolling and sliding contact with other bearing component in a boundary lubrication state; and the mixed layer is formed such that a content rate of the tungsten carbide in the mixed layer is continuously or stepwise decreased and a content rate of the diamond-like carbon is continuously or stepwise increased from a side of the foundation layer toward a side of the surface layer ; characterised in that the inner ring , the outer ring , and the rollers are formed of iron-based material; and the content of the hydrogen in the mixed layer is less than 10 atom%. <EOS>