A THERMOCOUPLE (6) IS PROVIDED FOR DETECTING A TEMPERATURE OF THE TIP OF A NEEDLE ELECTRODE (1). THE THERMOCOUPLE (6) INCLUDES A TIP CONNECTING PORTION (18) WHERE THE TIPS OF A PAIR OF COATED WIRES (8, 9) ARE ELECTRICALLY CONNECTED TO EACH OTHER AND A TIP COATED PORTION WHERE THE TIP CONNECTING PORTION (18) IS COATED WITH POLYOLEFIN SYNTHETIC RESIN. THE TIP COATED PORTION IS BONDED AND FIXED TO THE NEEDLE ELECTRODE (1). THEY PROVIDE A NEEDLE ELECTRODE DEVICE FOR MEDICAL APPLICATION CAPABLE OF BEING COMPACT WITH THE NEEDLE ELECTRODE PROVIDED WITH THE THERMOCOUPLE AND OF DETECTING A TEMPERATURE USING THE THERMOCOUPLE WITH HIGH ACCURACY. (FIGURE 2)