Abstract: A wet stripping apparatus for removing unwanted film layers, such as a thick photoresist layer from a wafer surface after a solder bumping process and a method for using the apparatus are disclosed. The apparatus includes a tank body, a wafer holder, and a means for reciprocally moving the wafer holder in an up-and-down motion with at least one wafer mounted in the holder immersed in a stripper solution to a frequency of not higher than 100 cycle/min. The stripper solution utilized, which is suitably kept at a temperature of at least 50° C., contains dimethyl sulfoxide, tetramethyl-ammonium-hydroxide and water. After the stripping process, the wafer is rinsed in a quick dump rinse step and then spin dried for conducting subsequent fabrication processes on the wafer.