A remote controlled actuator includes an elongated spindle guide section (3) and a distal end member (2) fitted to a distal end thereof for alteration in attitude. The distal end member rotatably supports a spindle (13) for holding a tool (1). The spindle guide section includes a rotary shaft (22) for transmitting rotation of a tool rotation drive source (41) to the spindle. An attitude altering member (31) inserted in a guide hole (30a) is selectively advanced or retracted by an attitude control drive source (42). An initial attitude hold control unit (53a) controls the attitude control drive source so that an initial attitude holding force (F0) necessary to maintain the distal end member in the initial attitude can be applied to the attitude altering member. An attitude alteration control unit (53b) controls the attitude control drive source so that the attitude of the distal end member can be altered by a force (F5) larger than the initial attitude holding force.
