PURPOSE: To obtain a new aromatic diazonium salt useful as a positive type or negative type radiation-sensitive mixture to be used for covering a radiation- sensitive recording material and a photoreaction initiator.

CONSTITUTION: This is an aromatic or a heteroaromatic mono- or bisdiazonium 1,1,2,3,3,3-hexafluoropropanesulfonate such as 2,5-diethoxy-4-p- tolylmercaptobenzenediazonium 1,1,2,3,3,3-hexafluoropropanesulfonate. The exemplified compound is obtained by reacting 2,5-diethoxy-4-p- tolylmercaptobenzenediazonium with 1,1,2,3,3,3-hexafluoropropanesulfonic acid. The new compound is exposed to chemical radiation to form an acid. The new compound is combined with o-naphthoquinonediazide, etc., a melamine/ formaldehyde condensate, etc., and, if required, a binder (e.g. novolak, etc.), to give a radiation-sensitive mixture.