the mole ratio of pt ruo2 sno2 was 10 10 80 respectively c such measured pre substances i e sncl4 rucl4 and h2ptcl6 were put into isopropyl alcohol ipa solvent and then subjecting the solution to ultra sonic distribution a the electrode substrate prepared by 1 was dipped into the solution prepared by 2 for 5 seconds and dried by far infrared ray at 70 celsius degrees for 10 minutes b the electrode coated with electrode catalyst was incinerated at 480 celsius degrees for 1 hour at room atmosphere i oxygen overvoltage was detected using three electrode analyzing system employing i the electrode obtained from 3 as a working electrode ii carbon electrode as a counter electrode and iii saturated calomel electrode sce as a auxiliary electrode i the voltages according to time were detected under the condition of employing the electrode obtained from 3 as an anode stainless steel as a cathode and 1 mole h2so4 as an electrolyte respectively and imposing 20ka m sup u22a5 of voltage life time is determined at the time when voltage increases 1 substrate was prepared in the same way as the example 1 a the same procedure as the 2 i of example 1 was performed b each pre substance was measured off so that the mole ratio of pt ruo2 sno2 was 10 10 80 respectively 3 electrode coating step was perfomed in the same way as 3 of example 1 4 the same analysis process as 4 of example 1 was performed 1 the.