Image reading apparatus and image forming apparatus

An image reading apparatus comprising:

• a first transparent plate that supports an original document;
• a second transparent plate that is disposed adjacent to the first transparent plate such that at least a portion of the second transparent plate on a first transparent plate side is disposed on an upper side of the first transparent plate;
• a reading member that moves along a plate surface of the first transparent plate to read an image of the original document supported by the first transparent plate and is disposed on a lower side of the second transparent plate;
• a first positioning member that positions the reading member with respect to the second transparent plate in a plate thickness direction of the second transparent plate in a state where the reading member is disposed on the lower side of the second transparent plate;
• and
• a transporting member that transports an image of an original document to be read by the reading member that is positioned with respect to the second transparent plate by the first positioning member, in a linear shape along the second transparent plate on an upper side of the second transparent plate when seen from an original document width direction of the original document.