To provide a method for regenerating spent developer to obtain a regenerated developer of high purity.
Spent developer is electrdialyzed and subjected to a mixed bed ion-exchange apparatus to remove a photoresist by anion exchange and metal ions by cation exchange. After that, liquid quality is confirmed by a liquid quality confirmation device 1, and the liquid is measured by an absorptiometer to know whether the concentration of the photoresist is below a standard or not. When the concentration meets the standard, the liquid is subjected to membrane dialysis and treated further with active carbon, and the liquid quality is confirmed by a liquid quality confirmation device 2. When the concentration of the photoresist meets the standard, the liquid is sent to a concentration adjusting device, and the regenerated developer having a precision bearable to development operation is obtained only by adding water. The liquid whose photoresist concentration measured by the device 1 or the device 2 exceeds the standard is returned from the confirmation device to a previous process through a passage T1 or a passage T2 to be treated again.
IGARASHI NORIO
SHIMIZU KOJI
