We examined the thermal stability of organic inorganic hybrid bicelles, which are lipid bilayer nanodiscs encompassed by siloxane surfaces. The hybrid bicelles were formed with a binary lipid mixture consisting of a long-chain alkoxysilane lipid and a short-chain phospholipid. It was clarified that the hybrid bicelles maintained a discoid assembly in water beyond the temperature of the gel to liquid-crystalline phase transition of the face-forming long-chain lipid, at which conventional phospholipid bicelles are transformed spontaneously to vesicles.