Provided are a control apparatus and method for an exercise therapy device, including the following steps: calculating a first-order lag waveform of a waveform of the target value of the exercise physiological response as a corrected target value of the exercise physiological response using a response time constant; calculating a difference between the corrected target value of the exercise physiological response and the measured value of the exercise physiological response as an exercise physiological response deviation after correction; generating a command value for the exercise load based on the exercise physiological response deviation after correction, so that the exercise physiological response of the exerciser approaches the corrected target value of the exercise physiological response, to thereby control the exercise load to be applied to the exerciser.