Abstract: Penning trap is an advanced equipment of microplasmas. To find its electrostatic field,a general "degenerated analogy method" is presented. As an application of this method, the electrostatic field is simply solved by structural analysis programs. The numerical result is consistent with the experimental result. The structural analysis programs are widely implemented by engineers and researchers. The users can simply extend their function to solve the engineering field problems not belonging to structural mechanics.

Key words: penning trap, degenerated analogy method, structural analysis program