Effects of organic gases (1, 4-butanediol, n-hexane, phenol, and benzene) on the contact resistance (the electrical life and the mechanical life) and the sticking were evaluated. These effects were evaluated by using telecommunication relays from which the cases were removed. Contact materials were Au90Ag10(clad)/Ag40Pd60 (base). Test conditions were as follows: In the cases of the electrical life test and the mechanical life test: Load conditions: DC28 V, 100 mA and 0 V, 0 mA. Temperature: 85. Frequency: 5 Hz. Number of operations: 2,500,000 times. In the case of the sticking test: Load condition: DC96 V, 140 mA. Temperature: 50. Frequency: 5 Hz. Number of operations: 2,000,000 times. It was found that the electrical life was more than 2,500,000 times, the mechanical life was more than 2,500,000 times, and the sticking didnt occur in the case of 1, 4-butanediol. The electrical life was improved by adding 1, 4-butanediol to phenol and benzene, respectively.