A rotor for a thermal turbomachine, in particular a gas turbine, is configured to conduct a medium in its interior. In order to conduct the medium in the interior with low flow losses, it is provided that a rotor disk of the compressor has holes, in order to feed the medium from outside into the rotor interior. For improved temperature control of the rotor disk, the holes conduct the medium through the rotor disk counter to the flow direction in the compressor.