The objectives of the current study are to develop a scale for measuring “home helper’s professional identity” and to examine the relationship between “home helper’s optimistic attitude” and “home helper’s professional identity”. The self-administered mailed survey was conducted among the 600 home helpers working in the home help service stations in A prefecture. The response rate was 24.8%. The relationship between “home helper’s optimistic attitude” and “home helper’s professional identity” was examined as a causal model by using structure equation modeling. The results indicated the following : 1) the current scale was confirmed in the validity by a confirmatory factor analysis ; and 2) the “home helper’s professional identity” was significantly associated with “self-growth of home helper” and “optimism in difficult situations of home help practice” in the subscale of “home helper’s optimistic attitude.” In conclusion, the current study supported the hypothetical consideration in which optimism and self-growth in home help practice significantly affected the professional identity of home helpers.