Recently, organic materials have been widely used as insulators for electrical elements in various environmental conditions. The importance of this information for preventing fires in electric appliances and devices has been established, and the tracking and ignition of organic insulating materials has been investigated as the origin of fires. This paper describes the effects of temperature and flame-retardant on the discharge characteristics. The experiment was carried out by dc impulse voltage. The test samples of epoxy resin laminate with and without flame-retardant have been employed to investigate the effects of temperature on discharge energy in the range from 20 to 150°C. The changes of contact angle and discharge quantity are discussed with increasing temperature and adding flame-retardant. The solution droplet and placed on the plate of epoxy resin laminate in contact with the needle electrode. The author found that the contact angle decreased with increasing sample temperature, and decreased with adding the flame-retardant. As the test results, the droplet is easier to be extended to the opposite side electrode with applied positive bias voltage (as the voltage applied at plate electrode side) than with applied negative bias voltage (as the voltage applied at needle electrode side). The speed of extending length of droplet is faster with the sample of added flame-retardant than the sample of without flame-retardant. The discharge energy of every samples with added flame-retardant was larger than the samples of without flame-retardant. The author also found that with increasing temperature the discharge energy was increased.