Abstract: The disclosure relates to methods and solutions for precisely and rapidly etching a polyimide resin layer. Etching solutions of the present invention include 3–65% by weight of a diol containing 3 to 6 carbon atoms or a triol containing 4 to 6 carbon atoms, 10–55 % by weight of an alkali compound and water in an amount of 0.75–3.0 times the amount of the alkali compound, and can be used at 65° C. or more to rapidly etch a polyimide resin layer having an imidation degree of 50–98 % without unfavorably affecting the working atmosphere. Even if the resin layer is completely imidated after etching, the etching pattern of the resulting resin layer is not deformed with a decreased contamination by impurity ions as compared with those obtained using conventional etching solutions.