To provide a bubble sensing and circuit breaking device for a household production unit of soybean milk, bean curd, and water-rich bean curd, capable of preventing bubbles from being formed, by making a heater not operated when the bubbles are formed in a main body of the production unit, and therefore capable of preventing the production unit from being damaged.

This bubble sensing and circuit breaking device for the household production unit of the soybean milk, the bean curd, and the water-rich bean curd is composed of a grounding electrode E1, a signal electrode E2, an electrical resistance R28, a switching transistor Q10, a controller I.C 1, another electrical resistance R8, another switching transistor Q4, a heater coil Ra, and the other switching transistor Q6, wherein the grounding electrode E1 and the signal electrode E2 are each joined to two members selected from components mounted on the main body (1), the electrical resistance R28 is connected to the signal electrode E2, the switching transistor Q10 is connected to the electrical resistance R28, the controller I.C 1 is connected to the switching transistor Q10 and outputs a control signal for breaking the circuit when the bubbles are formed, the switching transistor Q4 is connected to the controller I.C 1 through the electrical resistance R8, the heater coil Ra is connected to the switching transistor Q4, and the switching transistor Q6 is connected to the switching transistor Q4.