Image reading apparatus and image forming apparatus

An image reading apparatus, comprising:

• a housing having a document table glass;
• a scanner device, arranged in the housing, configured to read an original document on the document table glass;
• a cover configured to be connected to the housing to be rotatable around a first rotation center line with respect to the housing between a closed position where the document table glass is covered and an open position;
• an adsorption board, arranged in a part at a housing side at the time the cover is positioned at the closed position, configured to have an adsorption surface adsorbing the original document, and be connected to the cover member to be rotatable around a second rotation center line parallel to the first rotation center line between a clamping position at which the original document is clamped between the adsorption surface and the document table glass at the time the cover is positioned at the closed position and a movement position at which the adsorption surface moves in a direction away from the first rotation center line with respect to the clamping position;
• and
• an electric circuit that controls adsorption of the original document on the adsorption surface of the adsorption board.