Abstract: The present invention provides etching solution for alloy steel such as stainless steel using ferric chloride, in which ferric chloride can be regenerated without carrying out an operation of removing chromium and nickel and while suppressing an increase in the amount of the etching solution, and an etching method using the etching solution. The etching solution is etching solution comprising ferric chloride and chromium ions or nickel ions, or etching solution comprising ferric chloride, chromium ions and nickel ions and comprising each type of metal ions in a metal composition ratio approximately equal to a metal composition ratio in alloy steel to be etched. The etching method is a method for etching alloy steel with etching solution comprising ferric chloride and comprising each type of metal ions in a metal composition ratio approximately equal to a metal composition ratio in the alloy steel.