The main aim of the Miller-Urey experiment was to check the oparin-Haldane hypothesis that postualted earth's atmosphere was reducing from natural compounds. They suggested that the power for synthesis of organic compounds came from the lighting and the UV radiation.
Results were apparatus included a warmed flask of water simulating the sea and the systems of the hydrogen, ammonia, methane, which was strongly reducing atmosphere on early earth. After that, they discharged simulated lightings and sparks in atmosphere. So, the atmosphere became cooled by a condenser. When Miller and Urey collected the result of analysis, they found that this experiment yielded different amino acids, which is found in organisms like alamine and glutamic.
With these results, Miller and Urey concluded that oparin-Haldane hypothesis was correct.