Measurements of the Sunyaev-Zeldovich ( hereafter SZ ) distorsion of the cosmic microwave background can give interesting physical informations on clusters of galaxies , provided that the electronic temperature of the gas is known .
Previous attempts to do so have used the electronic temperature determination obtained from the X-ray spectra .
However , if the intergalactic gas is not homogeneous , the X-ray emission will trace the denser component , and the temperature determination may not be relevant for the lower density gas which is dominating the SZ measurements .
Moreover , the X-ray brightness decreases very rapidly with the distance , which is not the case for the SZ effect .
Distant clusters might be detected from SZ measurements , whereas they are inaccessible to X-ray observations .
For these reasons , we have investigated the possibility to derive the electronic temperature of the gas from the SZ measurements in the submillimeter range ( \lambda \sim 300 - 600 \mu m ) .
We show that given the sensitivities of the future submillimeter space missions Planck Surveyor and FIRST , the electronic temperature of massive clusters ( Y _ { center } = 3 \times 10 ^ { -4 } ) can be determined with an accuracy ranging from 1 to 4 keV depending on its distance and the data available .

Key words : cosmic microwave background – intergalactic medium – galaxies : clusters : general