The effect of batch annealing conditions and austenitizing temperatures on the hardness and microstructural factors were examined by using 420J2 martensitic stainless steel. In spite of the similler hardness after batch annealing, the difference in hardness at the same austenitizing temperature was caused by changes in dissolved carbon during batch annealing. The highest hardness of the specimen was obtained at the batch annealing temperature of $820^{circ}C$ and austenitizing temperature of $1050^{circ}C$. The main factor affecting the final hardness of the cold annealed 420J2 specimen was proved to the austenitizing temperature rather than batch annealing temperature.