An image reading apparatus includes: a moving body on which a catch receiving portion is formed and which is movable in a predetermined direction; a fixing body on which a catching portion is formed to catch the catch receiving portion, and which is movable in a direction substantially orthogonal to the predetermined direction; a first position retaining portion for engaging a projected portion, formed on either one of a housing and the fixing body, with a first recessed portion formed on the other so that the fixing body can be retained in a position in which the catching portion catches the catch receiving portion; and a second position retaining portion for engaging the projected portion with a second recessed portion, formed on either the housing or the fixing body on which the first recessed portion is formed.