We have developed a scanning probe microscopy method for probing the local Seebeck coefficient of individual layers of a thin-film superlattice structure. Development of this method involved modifying an existing scanning tunneling microscope (STM) by inserting a relay switch to connect the STM tip and the sample to an electrometer for measuring the thermovoltage generated by the contact of the STM tip to the warm sample. This method was used to measure the local Seebeck coefficient in each of the 20 layers of a p-type AlAs/GaAs thin-film superlattice. The results show an enhancement of the Seebeck coefficient in the GaAs quantum well layers when compared to the measurement result on a thick GaAs buffer layer with the same doping concentration as in the quantum wells