An external combustion engine including a container 10 sealed with a working medium 14 in liquid phase adapted to flow, a multiplicity of evaporators 201 to 204 for heating and evaporating part of the liquid-phase working medium 14, a multiplicity of condensers 221 to 224 for cooling and condensing the working medium 14 evaporated in the evaporators 201 to 204, and an output unit 11 for outputting by converting the displacement of the liquid-phase portion of the working medium 14 into mechanical energy. The multiplicity of the evaporators 201 to 204 share a heat source from which heat is supplied thereto. The engine further includes an influent liquid amount regulation unit whereby the liquid-phase portion of the working medium 14 in a greater amount flows into the evaporators nearer the heat source upon displacement of the liquid-phase portion of the working medium 14 toward the multiplicity of the evaporators 201 to 204 from the output unit 11, while the influent liquid amount is smaller for the evaporators farther from the heat source. In this way, heat loss is reduced resulting in improved efficiency.