A support unit configured to be inserted in a main body of an image forming apparatus thus to be mounted therein, the support unit comprising: a wall portion provided on an upstream end portion of the support unit in an insertion direction in which the support unit is inserted; a connector unit provided on the wall portion for electrical connection between the main body and the support unit; a screw hole (31F2) having its opening on the wall portion and into which a screw to be used to fix the support unit to the main body is inserted; and a cover member pivotably supported by a bearing portion provided on the wall portion, so as to pivot between a first position in which the connector unit is exposed and a second position in which the connector unit is concealed, wherein the cover member includes, in the second position, a second wall portion extending in a direction intersecting the insertion direction and a first wall portion extending from the second wall portion in the insertion direction so as to intersect the second wall portion, and in the first position, the second wall portion extends in the insertion direction, and the first wall portion is located upstream of the position where the first wall portion is located when the cover member is in the second position, and extends in the direction intersecting the insertion direction, wherein the support unit is characterized in that in the wall portion, the screw hole (31F2) is formed at a position deviated in the direction intersecting the insertion direction from an end portion of the second wall portion being in the second position, the wall portion includes a second space extending in the insertion direction and located upstream of the screw hole (31F2) in the insertion direction, the cover member further includes a third wall portion formed at the end portion of the second wall portion, the third wall portion extending, in the second position, in the direction intersecting the insertion direction so as to cover the screw hole (31F2), and the third wall portion is disposed to extend in the insertion direction so as to open the second space when the cover member is in the first position, and is disposed to intersect the insertion direction so as to cover the second space when the cover member is in the second position. a wall portion provided on an upstream end portion of the support unit in an insertion direction in which the support unit is inserted; a connector unit provided on the wall portion for electrical connection between the main body and the support unit; a screw hole (31F2) having its opening on the wall portion and into which a screw to be used to fix the support unit to the main body is inserted; and a cover member pivotably supported by a bearing portion provided on the wall portion, so as to pivot between a first position in which the connector unit is exposed and a second position in which the connector unit is concealed, wherein the cover member includes, in the second position, a second wall portion extending in a direction intersecting the insertion direction and a first wall portion extending from the second wall portion in the insertion direction so as to intersect the second wall portion, and in the first position, the second wall portion extends in the insertion direction, and the first wall portion is located upstream of the position where the first wall portion is located when the cover member is in the second position, and extends in the direction intersecting the insertion direction, wherein the support unit is characterized in that in the wall portion, the screw hole (31F2) is formed at a position deviated in the direction intersecting the insertion direction from an end portion of the second wall portion being in the second position, the wall portion includes a second space extending in the insertion direction and located upstream of the screw hole (31F2) in the insertion direction, the cover member further includes a third wall portion formed at the end portion of the second wall portion, the third wall portion extending, in the second position, in the direction intersecting the insertion direction so as to cover the screw hole (31F2), and the third wall portion is disposed to extend in the insertion direction so as to open the second space when the cover member is in the first position, and is disposed to intersect the insertion direction so as to cover the second space when the cover member is in the second position.