Why is thermostable DNA polymerase required for PCR?

Thermostable DNA Polymerase does not denature at very high temperatures, which makes it very useful for PCR. 

PCR (Polymerase chain reaction) is a technique that’s used to quickly generate millions of copies of a specific DNA segment to be used for more in-depth analysis. In PCR, a section of the genome to be amplified goes through multiple cycles of DNA synthesis at different temperatures, which allows numerous copies of the target region to be generated. During the process, the temperature can rise to around 60°C, causing denaturation of most enzymes. DNA polymerase is the best enzyme for PCR because it is thermostable and does not denature at higher temperatures.