Provided is a wave power generation device improved in power generation efficiency and a method of controlling the same, the wave power generation device generating electric power by extracting energy from a wave. The wave power generation device includes: a wave sensor configured to measure the waveform; a position sensor configured to measure a position of a float relative to a column; a drive mechanism configured to apply an external force to the float; and a controller configured to control the drive mechanism. The controller is configured to calculate a speed at which the float is to be controlled to move, from values of the wave sensor and the position sensor, and to control the drive mechanism in such away that the float moves at the calculated speed.