This section explains that relatively small- and medium-sized linear motors used in industrial fields are classified into four types based on their operating principles and describes the basic characteristics of each type. Next, methods for evaluating the characteristics of linear motors are explained and indices for evaluating the characteristics are presented. Furthermore, to evaluate the characteristics of linear motors, the relationship between thrust and tangential stress is explained, the field distribution with conventional magnet arrangements, repulsive magnet arrangements, and Halbach magnet arrangements are compared, and examples of increasing thrust by devising the direction in which magnetic flux flows are given. It also shows examples of high-performance linear synchronous motors and the development of a permanent magnet field type and a reluctance type. Finally, the motor constant squared density values of these synchronous motors are compared.