Provided is a tool tip position detecting device (53) for a remote controlled actuator (5) having an elongated spindle guide (3), a tool (1) fitted to a tip thereof and a main body housing (4) having a base end of the spindle guide (3) connected thereto. The device (53) includes an external force free position detector (54) for detecting the tip position of the tool (1) from a detection value thereof, a strain detector (60) for detecting a strain of the spindle guide (3), and a corrector (55) for correcting the tip position of the tool (1), which has been detected by the external force free position detector (54), with the use of a detected strain value of the strain detector (60).