The usage of the Permanent Magnet Linear Synchronous Motors has been largely increased these days. Use of Permanent Magnet Linear Synchronous Motors is more considered especially when reciprocating movement is needed. Existence of the detent force is one of the disadvantages of these motors compared with rotating motors. This force is one the most effective subjects which makes errors in determining exact position of the moveable part. At first, some different analysis of Permanent Magnet Linear Synchronous Motors are mentioned in this report and then Finite Element Method is applied as the best solution. It is shown that the detent force effect could be eliminated largely, although it requires small changes in the structure of the model. At last, after introducing the necessary modifications to the method, the best situation to minimize the detent force is offered.