A rotary moto actuator with a base 22, a table 21, a stator 25 and a rotor 26 of a rotary motor 31 and a first member 12 and a second member 14 of a guide mechanism 24 that have a plurality of base segments 22a, a plurality of table segments 21a, a plurality of stator segments 25a, a plurality of rotor segments 26a, a plurality of first member segments 12a and a plurality of second member segments 14, respectively, which all arranged circumferentially around a center line C. The stator segments 25a are connected to the base segments 22a, to which the first member segments 12a are connected. The rotor segments 26a are connected to the table segments 21a, to which the second member segments 14a are connected.