A controller constituting a construction machine includes: a target value computing unit that generates a speed target value of a boom based on a lever manipulating signal; a target value correcting unit that corrects the speed target value; and a command signal output unit that outputs a command signal to a boom driving device based on the corrected speed target value. The target value correcting unit includes: a motion information acquiring unit that acquires motion information on a motion of an arm; a maximum value determining unit that determines based on the motion information a maximum correction value for reducing suppression of a floating motion by a floating motion suppressing unit as the motion of the arm becomes faster; and a correction value regulating unit that corrects the speed target value based on the maximum correction value.