An image forming apparatus includes: a main body casing; a fixing unit accommodated in the casing and including a heating member and a pressing member; a first wall provided inside the casing at a position above the heating member and the pressing member and extending diagonally downward and forward; an uneven portion provided on the first wall at a position rearward of front end portion of the pressing member to restrain a dew droplet condensed on the first wall from running down along the first wall; a sheet ejection opening formed in the casing such that the recording sheet conveyed out from the fixing unit is ejected outside the casing through the sheet ejection opening; and an exhaust opening formed in the casing at a position rearward of the heating member such that air heated in the fixing unit is discharged outside the casing through the exhaust opening.