PURPOSE: To dispense with troublesome manual operations such as changeover of switches, changeover of connection of circuits and an operation of a measuring probe, by changing measuring conditions sequentially by a measuring device and by taking in measured values thus obtained.

CONSTITUTION: A measuring device 7 comprises CPU 22 constituted of a microprocessor having a plurality of input/output ports, and memories, as main units. An alternating- current input voltage switching circuit 2, an input signal switching circuit 6, a load switching circuit 5 and an A/D converter circuit 8 are connected to CPU 22. The circuits 2, 6 and 5 switch over an input alternating-current voltage, an input signal level, a waveform and a loaded state respectively in accordance with measuring conditions inputted as digital values from CPU 22 respectively. The circuit 8 converts a measured value of the voltage or a current in a prescribed part at the time of operation of a switching regulator 3 into a digital value and inputs same to the CPU 22. Measured values obtained by changing various measuring conditions are outputted to a recording device 21. In this way, the operation of an operator is required only for inputting the measuring conditions, and manual operations for changing over connections of circuits and others are dispensed with entirely.