The Automated Transfer Vehicle (ATV) is one of the major European contributions to the International Space Station Alpha (ISSA). The ATV will be launched with ARIANE 5 and will be used for servicing of ISSA with pressurized and unpressurized cargo as well as for ISSA refuelling and reboost.The ATV consists of a Core Module and a Cargo Module. The Core Module includes all major subsystems including the propellant tanks required for the automated flight to ISSA. Eight 400 N thrusters are accommodated on the bottom platform for orbit transfer and reboost of ISSA. Twenty 200 N thrusters, accommodated on the cylindrical shell of the core module, are provided for attitude control.The thermal control of the ATV consists of a passive subsystem supported by an electrical heater system. The waste heat of most of the avionics equipment is collected and transferred via conduction through the box baseplate to the avionics platform and further on to the cylindrical shell. As radiator to space the Micro-meteoroid and Debris Protection Shield (MDPS) is used.This paper gives an overview of the different design options which were investigated during Phase B of the ATV program and summarizes the finally chosen thermal control concept.