In a broth-manufacturing apparatus, a container is applied to contain a broth. A heater is applied to heat the broth. A first sensing element is disposed at the container and senses the broth and generates a first voltage signal. A second sensing element is disposed at the container and senses the broth and generates a second voltage signal. The disposed position of the first sensing element is lower than that of the second sensing element. A third sensing element is disposed at the container and senses the broth and generates a third voltage signal. The disposed position of the second sensing element is lower than that of the third sensing element. The control unit is electrically connected with the first sensing element, the second sensing element, the third sensing element and a heating element. The control unit starts a beating process of the broth-manufacturing apparatus or not according to the difference of the first voltage signal and the second voltage signal or the second voltage signal, and controls the heating element to heat the broth or not according to the difference of the first voltage signal and the third voltage signal.
