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.
