This paper elaborates on the idea of using the scanning tunneling microscope in new experiments on thermopower generation by a vacuum-tunneling junction. We first introduce the subject of thermopower generation in metals in the presence of a temperature gradient, emphasizing the physical origins of the thermopower. Then we discuss a thermopower produced in a homogeneous metallic chain containing a tunneling junction. This thermopower is sufficiently large to be measured. Finally, we describe an arrangement to measure the thermopower, especially with the help of the scanning tunneling potentiometry.