An image forming apparatus comprising: an image forming unit (21, 22, 23, 24, 25, 26); a frame structure forming a housing structure including an internal space that accommodates the unit (21, 22, 23, 24, 25, 26), the frame structure including at least one metal side plate frame having an inner side surface facing the internal space and an outer side surface opposite the inner side surface; a plurality of rotational shafts; a plurality of drive gears (51, 52, 53, 54, 55) each rotating about an axis of the rotational shaft; a resin drive housing including a supporting side surface that supports one end of the rotational shaft and a cavity in which the plurality of drive gears(51, 52, 53, 54, 55) is accommodated, the drive housing being open at another end of the rotational shaft; a high voltage substrate that carries, on one surface thereof, an electric component for operating the image forming unit (21, 22, 23, 24, 25, 26); and a connecting member (61, 62, 63, 64) made of a conductive metal and including a lead wire (613, 623, 633, 643), a first terminal member (612, 622, 632, 642) provided at one end of the lead wire (613, 623, 633, 643) and serving as a contact for supplying power to the image forming unit (21, 22, 23, 24, 25, 26), and a second terminal member (611, 621, 631, 641) provided at another end of the lead wire (613, 623, 633, 643), wherein the drive housing includes a substrate supporting portion that supports the high voltage substrate, characterized in that the drive housing is attached to the side plate frame such that the opening of the drive housing is sealed by the inner side surface of the side plate frame, the drive housing has electrical insulation and holds the connecting member (61, 62, 63, 64), the high voltage substrate includes, on the one surface on which the electric component is carried, a contact portion (71, 72, 73, 74) electrically connected to the electric component, and the second terminal member (611, 621, 631, 641) is disposed at the substrate supporting portion, and the contact portion (71, 72, 73, 74) and the second terminal member (611, 621, 631, 641) come into contact with each other in a state in which the high voltage substrate is supported by the substrate supporting portion. an image forming unit (21, 22, 23, 24, 25, 26); a frame structure forming a housing structure including an internal space that accommodates the unit (21, 22, 23, 24, 25, 26), the frame structure including at least one metal side plate frame having an inner side surface facing the internal space and an outer side surface opposite the inner side surface; a plurality of rotational shafts; a plurality of drive gears (51, 52, 53, 54, 55) each rotating about an axis of the rotational shaft; a resin drive housing including a supporting side surface that supports one end of the rotational shaft and a cavity in which the plurality of drive gears(51, 52, 53, 54, 55) is accommodated, the drive housing being open at another end of the rotational shaft; a high voltage substrate that carries, on one surface thereof, an electric component for operating the image forming unit (21, 22, 23, 24, 25, 26); and a connecting member (61, 62, 63, 64) made of a conductive metal and including a lead wire (613, 623, 633, 643), a first terminal member (612, 622, 632, 642) provided at one end of the lead wire (613, 623, 633, 643) and serving as a contact for supplying power to the image forming unit (21, 22, 23, 24, 25, 26), and a second terminal member (611, 621, 631, 641) provided at another end of the lead wire (613, 623, 633, 643), wherein the drive housing includes a substrate supporting portion that supports the high voltage substrate, characterized in that the drive housing is attached to the side plate frame such that the opening of the drive housing is sealed by the inner side surface of the side plate frame, the drive housing has electrical insulation and holds the connecting member (61, 62, 63, 64), the high voltage substrate includes, on the one surface on which the electric component is carried, a contact portion (71, 72, 73, 74) electrically connected to the electric component, and the second terminal member (611, 621, 631, 641) is disposed at the substrate supporting portion, and the contact portion (71, 72, 73, 74) and the second terminal member (611, 621, 631, 641) come into contact with each other in a state in which the high voltage substrate is supported by the substrate supporting portion.