An image forming apparatus includes a lower casing, an upper casing, an arm, and a brake member. The lower casing includes a photosensitive body. The upper casing includes an exposure unit configured to expose the photosensitive body. The upper casing is configured to pivot on a predetermined axis relative to the lower casing between a closed position where the upper casing covers an upper portion of the lower casing and an open position where the upper casing exposes the upper portion of the lower casing. The slider is attached to the upper casing and is configured to slide in a sliding direction orthogonal to the predetermined axis. The arm includes a first end pivotably connected to the lower casing and a second end pivotably connected to the slider. The brake member is configured to control a speed of the slider when the slider slides in the sliding direction.