A power generator using a floating object and exhibiting further improved power generation efficiency includes a floating object including a floating body arranged to catch wind, a plurality of posture control strings, and a posture control instrument, at least one first control string connected to the posture control instrument, a first control string take-in device arranged to take the at least one first control string into a first base body, a forward/backward movement control device arranged to control forward/backward movements of the posture control strings, a first winding device arranged to wind a proximal send of the at least one first control string, a second control string connected to the posture control instrument, a second control string take-in device arranged to take the second control string into a second base body installed apart from the first base body, and a second winding device around which a proximal end of the second control string is wound. The at least one first control string or the posture control instrument that mounts a communication device is arranged to control a front/rear inclination angle .theta. of the floating object, and the second control string is reeled out/taken up in accordance with the front/rear inclination to generate electric power.