An intermediary transfer belt includes a base layer; an elastic layer laminated on or above the base layer and formed with a silicone rubber as an elastic member; an intermediary layer laminated on or above the elastic layer; and a surface layer laminated on or above the intermediary layer. The elastic layer is 60 degrees or less in JIS-A hardness and is 5 degrees or more in JIS-E hardness. The intermediary layer is 0.1 g/m2·24 h or more and 600 g/m2·24 h or less in water vapor permeability coefficient and is 1 μm or more and 15 μm or less in average thickness.