A turning drive control unit configured to control driving of the rotation mechanism of a construction machine driven to turn by an electric motor includes a drive command output part configured to output a speed command driving the electric motor based on the amount of operation input via the operation part of the construction machine; a rotation speed detection part configured to detect the rotation speed of the electric motor; and a drive command generation part configured to generate a drive command driving the electric motor based on the speed command output from the speed command output part and the rotation speed detected by the rotation speed detection part. At a time immediately before a rotation stop of the electric motor, the drive command generation part causes the braking torque of the electric motor to be smaller than before the time immediately before the rotation stop.