Patent ID: 6875359

Claim:
A developer waste liquid regenerating apparatus comprising: a developer waste liquid transportation member which transports developer waste liquid containing tetraalkylammonium hydroxide and a photoresist, a first storage tank which stores said transported developer waste liquid, first separating means with a first nanofiltration membrane, which separates the developer waste liquid stored in said first storage tank into a tetraalkylammonium hydroxide-containing first permeating liquid and a first non-permeating component, the first nanofiltration membrane having a molecular weight cutoff of 700 to 1300. a second storage tank which stores said first permeating liquid, and second separating means with a second nanofiltration membrane having a different molecular weight cutoff from said first nanofiltration membrane, which separates the first permeating liquid stored in said second storage tank into a second permeating liquid and a tetraalkylammonium hydroxide-containing second non-permeating component, the second nanofiltration membrane having a molecular weight cutoff of 100 to 300.