The mVINIS Ion Source is a part of the TESLA Accelerator Installation whose construction has been going on in the VINČA Institute of Nuclear Sciences in Belgrade. The main parts of the mVINIS Ion Source was designed and manufactured in the Joint Institute for Nuclear REsearch in Dubna, Russia. The first ion beam was obtained in September 1997. After compelting its safety system and improving control system, in the beginning of 1998, we have started commissioning of the mVINIS. This paper presents ion yields and spectrums for some gases obtained during the first phase of commissioning.