An induction heater is a key piece of equipment used in all forms of induction heating. Typically an induction heater operates at either medium frequency (MF) or radio frequency (RF) ranges.

Four main component systems form the basis of a modern induction heater

Induction heating is a non contact method of heating a conductive body by utilising a strong magnetic field. Supply (mains) frequency 50 Hz or 60 Hz induction heaters incorporate a coil directly fed from the electricity supply, typically for lower power industrial applications where lower surface temperatures are required. Some specialist induction heaters operate at 400 Hz, the Aerospace power frequency.

Induction heating should not be confused with induction cooking, as the two heating systems are mostly very physically different from each other. Notably, induction heating systems work by applying an alternating magnetic field to a ferrous material to induce an alternating current in the material, so exciting the atoms in the material heating it up.^{[citation needed]}

An induction heater typically consists of three elements.

Often referred to as the inverter or generator. This part of the system is used to take the mains frequency and increase it to anywhere between 10 Hz and 400 kHz. Typical output power of a unit system is from 2 kW to 500 kW.

This contains a combination of capacitors and transformers and is used to mate the power unit to the work coil.

Also known as the inductor, the coil is used to transfer the energy from the power unit and work head to the work piece. Inductors range in complexity from a simple wound solenoid consisting of a number of turns of copper tube wound around a mandrel, to a precision item machined from solid copper, brazed and soldered together. As the inductor is the area where the heating takes place, coil design is one of the most important elements of the system and is a science in itself.