PURPOSE: To provide a method for preventing zincate liquid, etc., from entering below a resist pattern when an aluminum board is, after the board having specific % or more of relative hydration ratio is formed with the pattern, treated with zincate.

CONSTITUTION: After an aluminum board having 30% or more of relative hydration ratio is formed with a resist pattern, it is heat treated at 100-200°C, the ratio of an aluminum surface near an end of the resist is set to 10-30%, and then treated with zincate, etc. The board obtained in this manner can prevent, when it is treated with the zincate, etc., zincate liquid, etc., from entering below the pattern, and a printed circuit board having a small short-circuit by later plating can be manufactured.