To obtain alloy powder having a nallow size distribution a limited secondary flocculation and suitable for conductive paste by adding hydroxylammonium sulfate to an ammonia complex soln. contg. silver and palladium and executing reduction.

An ammonia complex soln. contg. prescribed ratios of silver and palladium is added with a protective colloid and is thereafter added with hydroxylammonium sulfate, and reduction treatment is executed. After the completion of the reduction reaction, silver-palladium powder precipitated into the mixed soln. is separated by a centrifugal separator, which is thereafter subjected to water cleaning and ethanol cleaning, and drying is executed to obtain the silver-palladium powder having the objective mixed ratio. The pH of the ammonia complex soln. contg. silver and palladium is preferably regulated to 10 to 14. The total ion concn. of silver and palladium. is preferably regulated to ≤100 g per 1 of the ammonia complex soln.