A thermoelectric power generator includes a pipe (7) in which a first fluid flows, and a power generation module (1) including a thermoelectric conversion element (2). The thermoelectric power generator includes a holding member (3, 4) that is in contact with a one side part of the power generation module, such that heat of a second fluid that is higher in temperature than the first fluid transfers to the one side part of the power generation module. The holding member holds the power generation module and the pipe in a heat transferable state, such that the pipe is in contact with the other side part of the power generation module. The thermoelectric power generator includes a heat conductive component (6) interposed between the holding member and the pipe to define a heat transfer course through which heat transfers from the second fluid to the first fluid, at downstream of the power generation module in a flowing direction of the second fluid.