MANUFACTURING METHOD OF SHADOW MASK, AND ETCHANT FILTERING DEVICE FOR SHADOW MASK

PROBLEM TO BE SOLVED: To provide an etchant filtering device for a shadow mask capable of preventing stripe irregularity failure from occurring in manufacturing the shadow mask, and avoiding or reducing a foreign matter getting mixed into the etchant from causing a hole shape failure for inhibiting the etching. SOLUTION: In this etchant filtering device for the shadow mask, the etchant is fed from an etchant tank 1 to an etching chamber 4 through an etchant supply system, and an etching process for opening a desired micro opening hole in a metal thin plate that has been applied with an etching pre-process for the shadow mask is performed in the etching chamber 4. The inside of etchant tank 1 is provided with a first filtering device 2 for filtering foreign matters contained in the etchant, and the etchant supply system from the etchant tank 1 to the etching chamber 4 has a second filtering device 3 for filtering foreign matters having grain sizes different from that for the first filtering device 2.