Image forming apparatus includes: main body casing having first and second side walls opposite to each other, and upper portion having opening; top cover swingably supported on the upper portion of the main body casing at a position near the second side wall and configured to openably close the opening; endless belt disposed below the top cover and having first end portion closer to the first side wall and second end portion closer to the second side wall; photoconductor drum disposed under the endless belt; development unit disposed under the photoconductor drum and configured to supply developer to the photoconductor drum; and fixing device disposed above the second end portion of the endless belt. The endless belt is configured to be swingable about axis of rotation provided near the second side wall such that the first end portion of the endless belt is swingable in an upper-lower direction.