A control device for use with a plastics processing machine, e.g. an injection molding machine, includes a housing which is constructed for protection against ingress of water in compliance with the IP code and accommodates a heat source such as a CPU unit or a display unit. A cooling system is provided for dissipating heat generated by the heat source and includes a pump for pumping a coolant, at least one cooling element arranged inside the housing, a cooler provided outside the housing, and a coolant circuit for circulation of the coolant. The coolant circuit fluidly connects hereby the pump, the cooling element and the cooler with one another.