| 摘要 |
PROBLEM TO BE SOLVED: To provide an etching method in which change of an etching place can be performed more easily without the number of processes being increased too much.SOLUTION: An aqueous solution 202 in which yeast is included and cane sugar is dissolved is accommodated in a container 201 comprising a semi-permeable membrane which yeast cannot pass, and a container 201 is made to be in proximity to a desired mask area 211 on a surface of a metallic component 204 covered by a water film 205. In a region in which a container 201 is in proximity to a surface of a metallic component 204 through a water film 205, zinc ions dissolved in a water film 205 intrudes in an aqueous solution 202 through a semi-permeable membrane of a container 201, and is reduced because yeast exists. |
