Provided are a hydrogen ion electrode composed of a composite material of polymer resin and nano iridium oxide, the composite material containing 1-10 nm sized nano iridium oxide particles and/or aggregates thereof which are dispersed to be electrically connected to each other in a moldable, thermoplastic, and hydrophobic polymer resin matrix; a pH sensor using the same; and a method for manufacturing the same. The surface of the hydrogen ion electrode shows very fast pH sensitivity when exposed to a sample solution, and the pH sensitivity is approximate to biphasic characteristics. Furthermore, regardless of high reproducibility of pH sensitivity, abrupt pH change, and repetitive use, very low hysteresis, durability due to high physical strength, and high surface regeneration due to polishing are exhibited, and thus, the lifetime of the electrode can be extended and various sizes and shapes of electrodes can be easily manufactured.