The prevalence of discogenic pain among patients with chronic low back pain is estimated to be about 40%. Lumbar discectomy is being performed as a treatment according to the studies done so far. Recently IDET- Intradiscal electrothermal therapy which is minimally invasive technique is being introduced. This study will investigate important factors of this procedure such as the temperature of heat source, loading times, and the temperature distribution within the intervertebral disc. This study utilized finite element analysis and experiment. It was able to analyze the temperature range of inner intervertebral disc by two mechanisms which are known to alleviate pain clinically. As a result, verification of temperature distribution to 15.6mm($geq$45$^{circ}C$) (Mechanism 1-coagulation inner annulus by heat) and 9mm($geq$6$0^{circ}C$) (Mechanism 2- contraction inner nucleus by heat) from the heat source was done.