An image forming apparatus capable of applying an adequate amount of fixing fluid to an unfixed toner image and producing high-quality images having high resolution and high image density with stability for a longer period of time while protecting the interior thereof against fixing fluid leakage and achieving reduction in fixing fluid consumption is provided. In an image forming apparatus, a fixing fluid is applied to a toner image on an intermediary transfer belt by a coating roller, and the toner image in a swollen/softened state is fixed onto a recording medium. By a second seal member composed of a film-shaped member and a supporting member, a gap between the coating roller and a fixing fluid chamber which has the opening and places the coating roller therein is closed to avoid leakage of the fixing fluid.