An image forming apparatus comprising: an image reading portion configured to read a document image; and an image forming portion configured to print the document image read by the image reading portion onto a receiving material, wherein the image forming portion includes a conductive ground member, and the image reading portion includes: a non-conductive casing configured to support a document platen on which a document is placed; a carriage that is accommodated in the casing and is provided so as to be capable of reciprocating movement with respect to the document platen; a flat cable that is disposed along a direction of the reciprocating movement of the carriage and is configured to input a synchronization signal into a board mounted on the carriage; a conductive plate that is supported by the casing such that, when portions of the flat cable face each other as a result of the flat cable being bent according to the reciprocating movement of the carriage, the conductive plate is interposed between the facing portions of the flat cable; characterized in that the image reading portion further comprises an elastic member that is configured to electrically connect the conductive plate and the ground member, and has a substantial inductance component and that absorbs vibration generated in the image forming portion or the image reading portion. an image reading portion configured to read a document image; and an image forming portion configured to print the document image read by the image reading portion onto a receiving material, wherein the image forming portion includes a conductive ground member, and the image reading portion includes: a non-conductive casing configured to support a document platen on which a document is placed; a carriage that is accommodated in the casing and is provided so as to be capable of reciprocating movement with respect to the document platen; a flat cable that is disposed along a direction of the reciprocating movement of the carriage and is configured to input a synchronization signal into a board mounted on the carriage; a conductive plate that is supported by the casing such that, when portions of the flat cable face each other as a result of the flat cable being bent according to the reciprocating movement of the carriage, the conductive plate is interposed between the facing portions of the flat cable; characterized in that the image reading portion further comprises an elastic member that is configured to electrically connect the conductive plate and the ground member, and has a substantial inductance component and that absorbs vibration generated in the image forming portion or the image reading portion. a non-conductive casing configured to support a document platen on which a document is placed; a carriage that is accommodated in the casing and is provided so as to be capable of reciprocating movement with respect to the document platen; a flat cable that is disposed along a direction of the reciprocating movement of the carriage and is configured to input a synchronization signal into a board mounted on the carriage; a conductive plate that is supported by the casing such that, when portions of the flat cable face each other as a result of the flat cable being bent according to the reciprocating movement of the carriage, the conductive plate is interposed between the facing portions of the flat cable; characterized in that the image reading portion further comprises an elastic member that is configured to electrically connect the conductive plate and the ground member, and has a substantial inductance component and that absorbs vibration generated in the image forming portion or the image reading portion.