Watch component and watch

An austenitic ferritic stainless steel comprising:

• a base portion composed of a ferrite phase;
• a surface layer composed of an austenitic phase;
• and
• a mixed layer formed between the base portion and the surface layer, and in which the ferrite phase and the austenitic phase are mixed wherein
• the base portion contains Cr:
• 18 to 22 mass %, Mo:
• 1.3 to 2.8 mass %, Nb:
• 0.30 to 0.50 mass %, Cu:
• 0.1 to 0.2 mass %, Ni:
• less than 0.5 mass %, Mn:
• 0.5 to 0.8 mass %, Si:
• less than 0.5 mass %, P:
• less than 0.10 mass %, S:
• less than 0.05 mass %, N:
• less than 0.05 mass %, C:
• less than 0.05 mass %, and a balance being composed of Fe and inevitable impurities, wherein
• the surface layer contains 1.0 to 1.6 mass % of nitrogen, wherein
• the surface layer includes, at a surface of the surface layer, an oxide film having a thickness of 2.5 nm or greater, as calculated using oxygen profiles obtained by AES analysis.