Photomask blank substrate container, method for storing photomask blank substrate and method for transporting photomask blank substrate

A photomask blank substrate container for containing a photomask blank substrate, comprising

• an inner member having an inner cassette capable of containing the photomask blank substrate, and a retainer member for fixing the photomask blank substrate contained in the inner cassette from above,
• a container main body having a lower box capable of containing the inner cassette, and an upper lid capable of engaging with the retainer member to an inside, and
• a sealing tape for sealing the container main body,
• the lower box engaging with the upper lid directly,
• wherein the container main body and the inner member comprise a polymer-based material in which when 0.1 g of a sample thereof is retained at 40° C. for 60 minutes to release an outgas component, a total amount of the outgas detected by a gas chromatography mass spectrometer is 500 ng or less in terms of n-tetradecane,
• the sealing tape is a material in which when a size of 10 mm×10 mm of a sample thereof is retained at 150° C. for 10 minutes to release an outgas component, a total amount of the outgas detected by a gas chromatography mass spectrometer is 1.0×103 ng or less in terms of n-tetradecane,
• the photomask blank substrate is a material onto which a chemical amplification type resist has been coated, wherein
• the container main body comprises a polymer-based material containing a polycarbonate as a main component, and a surface resistance value thereof is 2.0×104 Ω/sq or less, and
• the sealing tape has:
• (i) a substrate comprising a polymer selected from the group consisting of polyethylene terephthalate, polypropylene and polyethylene, and (ii) an adhesive surface comprising polyacrylic ester.