Disclosed is an energy converting apparatus for converting mechanical energy obtained by a fluid flow into electric energy. The energy converting apparatus comprises: a blade; a measuring device for measuring reaction of the blade when the fluid flow exerts an external force on the blade, and generating a measurement value corresponding to a measurement result; a memory for storing control values; a controller for reading a first control value among the control values from the memory in response to the measurement value output from the measuring device, and generating a control signal by using the first control value; and an actuator for changing a three-dimensional shape of the blade in response to the control signal output from the controller.