The present invention provides a scanner apparatus provided with both a flatbed-type mechanism and an ADF-type mechanism. The ADF mechanism can be set at an arbitrary position with an arbitrary orientation for use, whereby convenience for the user is improved while ensuring freedom with regard to the setting place of the apparatus. Further, the scanner apparatus is made such that reading with the ADF unit and reading with the flatbed unit can be performed simultaneously. A movable coupling mechanism is provided at a joint portion between the ADF mechanism and the flatbed mechanism. The movable coupling mechanism does not fix the position and orientation of the ADF mechanism and enables the ADF mechanism to be freely moved and rotated. With this movable coupling mechanism, the ADF mechanism can be disposed at either of the left and right ends of the paper-pressing board of the flatbed unit or at an arbitrarily position in consideration of convenience for a user and the setting place of the apparatus. Further, the orientation of the shooter of the ADF mechanism can be freely changed.