An image forming apparatus comprising: a paper feeding cassette which selectively stores at least two kinds of paper sheets having different size with respect to a paper feeding direction, and includes a posterior end cursor which restricts a posterior end position of the stored paper sheets with respect to the paper feeding direction, wherein the height of the posterior end cursor is changeable. According to this construction, a smaller space is provided to stack large-sized paper sheets which are not frequently used while a larger space is provided to stack small-sized paper sheets which are frequently used can be reserved.