**8. Conclusions**

It this chapter, we introduced the dielectric phenomena of PI and PAI materials using space charge measurement results using the PEA method. And you could understand the PEA method is very useful for understanding the charge accumulation phenomena. However, the PI is applied for various condition, it is necessary that the measurement system should be modified for the condition and environment *Space Charge Accumulation Phenomena in PI under Various Practicable Environment DOI: http://dx.doi.org/10.5772/intechopen.96786*

applicable. And then, we could discuss the dielectric phenomena. From the described above, although we could understand the PI has a good insulation performance, since the characteristics may deteriorate depending on the environment, an analysis simulating the usage environment is required.
