A thrust needle roller bearing has a washer formed of a thin steel plate
and needle rollers, at least said washer has a nitrogen enriched layer at
a surface layer portion, amount of retained austenite in said surface
layer portion is at least 5 volume % and at most 25 volume %, and
austenite grain number of said surface layer portion is 11 or higher.
Thus, a long life thrust needle roller bearing resistant to an early
failure caused by surface damage such as surface-originated flaking and
also resistant to common, load dependent rolling contact fatigue can be
provided.