An image reading apparatus includes a first housing, a second housing, an imaging sensor, a reference member provided to be able to move between a first position facing the imaging sensor and a second position, a cam to make the reference member move, and an abutting member provided to make the cam move. The abutting member is located at a projecting position sticking out from the first housing, to make the cam move so that the reference member moves from the first position to the second position when the second housing is closed with respect to the first housing. The abutting member is provided so as to be able to retract when the second housing is opened and closed with respect to the first housing and abuts against the cam in the state located at the projecting position.