Disclosed are a scanner and an image reading apparatus including the same. The scanner can include a transparent plate, a scanning unit configured to scan a document on the transparent plate, a first sensor and a second sensor. The first sensor is positioned in a first document zone that is associated with an area in which a first document type is to be positioned based on a first alignment reference point provided on the transparent plate. The second sensor is positioned in a second document zone that is associated with an area in which a second document type of a different size is positioned based on a second alignment reference point provided on the transparent plate. The first document zone and the second document zone are non-overlapping zones. The document type and/or orientation can be determined based on the detection signals from the first and second sensors.