PROBLEM TO BE SOLVED: To prevent a malfunction caused by a temperature rise of a drag mechanism in an electric reel.SOLUTION: A control system 90 is a control device of an electric reel that comprises a spool 10, a drag mechanism 44, and a motor 12 for driving the spool 10. The control system 90 comprises a temperature sensor 29 and a reel control unit 23. The temperature sensor 29 is provided around the drag mechanism 44 and measures a temperature caused by the operation of the drag mechanism 44. The reel control unit 23 regulates the rotation of the motor 12 of the electric reel 100 when the temperature sensor 29 measures a first predetermined temperature Td.