Authors have been developing a spherical container having an inner wall constructed with skeletal ceramic units for transporting molten aluminum. This container is expected to provide innovative weight reduction and higher heat retaining property compared with current cylindrical containers having an inner wall made of castable refractory. In this study, a spherical inner wall with a combinative structure was designed: molten contacting part of the inner wall was constructed with skeletal unit made of reaction bonded silicon nitride (RBSN), while the non-contacting part with molten was constructed with skeletal unit made of aluminum titanate (AT). The quantity of heat emission from the container, temperature drop of molten in the container and thermal stress at the inner wall, while holding the molten, were simulated by heat transfer analysis. As a result, the spherical container reduced the quantity of heat emission compared with an inner wall constructed with only the RBSN unit, and was more reliable compared with that with only the AT unit. Thus, the new inner wall which enables a combination of light weight, high heat retaining property and reliability was proposed.