This paper focuses on the relationship between the composition of foam glass and its thermal conductivity and density. In this experimental research, three levels of glass particle size and foaming agent (SiC) quantity were tested. The results showed that the thermal conductivity increased by increasing the ratio of fine glass particles. On the contrary, the thermal conductivity was not affected by changing the foaming agent weight ratio. The density of foam glass increased by decreasing the foaming agent ratio, and there was no linear relation between the size of glass particles and the density of foam glass.