A method for manufacturing an LED die includes following steps: a semi-finished LED die is provided; an N-type layer, an active layer, and an P-type layer are sequentially formed on the transparent substrate; the transparent substrate is etched by laser to form a light outputting surface, the light outputting surface having a smoothly concave and arc-shaped configuration; common parts of the active layer and the P-type layer are removed to expose a part of the N-type layer; and an electrode structure is disposed on exposed N-type layer and the p-type layer to complete the formation of the LED die.