A method of manufacturing a display panel includes forming a circuit layer including a gate, a source, and a drain on a base substrate and forming a light emitting element layer on the circuit layer. The forming of the circuit layer includes sequentially forming a preliminary metal layer, a preliminary oxide layer comprising molybdenum and tantalum, and a preliminary capping layer which comprise a preliminary electrode layer, cleaning the preliminary electrode layer, forming a photoresist layer pattern on the preliminary electrode layer, etching the preliminary electrode layer, and removing the photoresist layer pattern. During the etching of the preliminary electrode layer, a ratio between a removal speed ER1 of the preliminary oxide layer and a removal speed ER2 of the preliminary metal layer satisfies Equation 1 to maintain a low reflection property 1≤ER2/ER1≤3.  [Equation 1]