Disclosed is a method of manufacturing an a-IGZO TFT-based transient semiconductor. The method includes (a) stacking a thermal oxide layer on a silicon substrate and depositing a nickel thin layer; (b) forming a PECVD layer on the nickel thin layer; (c) patterning the PECVD layer after setting a gate area and depositing a metallic layer; (d) lifting off the metallic layer to form a gage metallic thin layer and depositing a gage insulating layer on the gate metallic thin layer; (e) depositing an a-IGZO layer on the gate insulating layer; (f) etching an active area and the gate insulating layer; (g) forming a source electrode and a drain electrode and attaching a thermal release tape on the source electrode and the drain electrode; (h) delaminating the nickel thin layer; (i) performing transcription on a polyvinyl alcohol thin layer after etching the nickel thin layer; and (j) detaching the tape.