A multimeter is an electronic measuring instrument that combines several functions in one unit. The most basic instruments include an ammeter, voltmeter, and ohmmeter.

Other features available in some units:

• A continuity tester that beeps when a circuit conducts.
• Digital output (as a number, rather than a scale reading) of the quantity under test.
• An amplifier to sense small voltages, currents and high resistances.
• Measurements of inductance and capacitance. This is helpful to test components, and therefore much used by technicians that must build and repair equipment.
• Tests of diodes and transistors. This is popular with technicians who have to fix broken equipment.
• Scales and sockets for temperature measurement with standard thermocouples.
• An intermediate-frequency oscillator, a detector and an audio amplifier with a speaker, to diagnose and tune radio circuits. This used to be standard on some Russian models. It is an inexpensive compact substitute for an oscilloscope. It permits one to hear a signal, rather than see it.
• A slow oscilloscope. This is appearing in some high-end computer-controlled multimeters.
• A telephone test set.
• Automotive circuit tester.
• Record high and low voltage snapshots