An image forming apparatus includes an application device. The application device has an application roller to apply a treatment liquid onto a recording medium before an image is formed on the recording medium. The application roller has a core member serving as a rotation shaft of the application roller and an elastic surface member disposed around the core member. The core member has a plurality of convex ring portions formed along a circumferential direction of the core member around a circumferential surface of the core member and a plurality of concave ring portions formed between the plurality of convex ring portions. The convex ring portions and the concave ring portions are alternately arranged.