An image reading apparatus includes a conveyance unit, a reading unit, a carriage, a motor, a motor gear, a conveyance gear, a carriage gear, and a control device. The conveyance unit is configured to convey a document. The reading unit is configured to read an image on the document. The carriage is configured to support the reading unit and to be movable in a prescribed direction. The reading unit is selectively operable in a first mode in which the image on the document is read while conveying the document by the conveyance unit, and a second mode in which the image on the document is read by moving the reading unit in the prescribed direction. The switching gear is configured to be placed in a first position and a second position. The control device is configured to control the switching gear to move between the first position and the second position, acquire initialization data initializing the reading unit, and control the reading unit to read the image on the document. The control device acquires the initialization data while controlling the switching gear to move between the first position and the second position.