Amplitude modulated helium atomic magnetometers (AM He AOM) are proposed as a new method, which allows spatially resolved magnetic field measurement in the inner regions of burning plasmas without heating beams nor impurity atoms. In order to understand the fundamental properties of AM He AOM, we have developed a prototype, and Helium discharge lamp as well as its power supply has been also elaborated as a light source. 1083 nm AM emission was successfully obtained in the frequency range between 40 kHz and 500 kHz. We have performed an exploratory experiment of test magnetic field measurement with the developed AM He AOM. For the test magnetic fields: 2.6 µT and 5.0 µT, possible signs of magnetic field have been observed.