PURPOSE: To prevent the breakage of a semiconductor amplifying circuit and the like by a method wherein a fusible element is fused to stop a circuit when unbalance is generated in a compounding and distributing circuit for high frequency electric power.

CONSTITUTION: In the case of Wilkinson resultant and distribution circuit having two sets of circuit, for example, respective two pieces of resistors (r) and fixed capacitors (c) are connected in series to a fusible element 2 while an unbalance preventing circuit 7 is formed by connecting both ends of the fusible element 2 to the output terminals of a control circuit 3. When the fusible element 2 is fused due to the unbalance of the resultant and distribution circuit, the input of the control circuit 3 is changed from short-circuit into open circuit and an input voltage is changed suddenly from zero into an unbalance voltage between terminals T1, T2 whereby a control voltage is sent from the output terminal TA of the control circuit 3 into a power supply circuit to stop the resultant and distribution circuit. According to this method, the breakage of a semiconductor amplifying circuit and the like can be prevented.