Abstract: A cut sheet feeding device having a function of detecting a skew of the sheet to be fed is incorporated in an image reader, a printing apparatus, etc. The cut sheet feeding device is capable of surely detecting the skew of a document without an operator visually monitoring the same. The cut sheet feeding device has size sensors corresponding to standard sheet sizes, respectively, for detecting the size of a document that is being fed along a feeding path. The detected document size is compared with a set document size stored in advance. If the detected document size is greater than the set document size, it is determined that there is an abnormality in feeding the document. The cut sheet feeding device also has a document passage detector for detecting the passage of the document. The outputs of the document passage sensor and size sensor are compared with each other, to calculate a skew of the document that is being fed. This skew is used to determine whether or not the document is being fed normally.