PURPOSE: To determine the operation of a weighing apparatus accurately and automatically by checking the operation using a signal related to a varied parameter from a capacitance detection circuit.

CONSTITUTION: The weighing apparatus comprises a variable capacitance load cell 20, and a capacitance detection circuit 22 generating an analog signal indicative of the weight of the load cell 20. An analog weight signal from the circuit 20 is converted through an A/D converter 25 into a digital value which is transmitted to a microcomputer 28. The computer 28 compares the weight signal received from the converter 25 with a determination value stored in a memory 30 and presents the comparison results on a display 31. The determination value is the difference between the reading of weight when no load is applied to the weighing apparatus and a reading obtained after a determination circuit 35 is instructed by the computer 28 to vary the value of the parameter in the circuit 22.