An image forming apparatus, comprising: - a frame member; - an intermediate transfer unit that includes a drive roller, a tension roller, wherein the drive roller and the tension roller are supported by the frame member, and an intermediate transfer belt stretching around the drive roller and the tension roller; - a plurality of image forming units (10a, 10b, 10c and 10d) located at a lower side of the intermediate transfer unit and located along a running direction of the intermediate transfer belt; and - a plurality of toner containers (50a, 50b, 50c and 50d) located at an upper side of the intermediate transfer belt corresponding to the respective image forming units (10a, 10b, 10c and 10d) to supply the respective image forming units (10a, 10b, 10c and 10d) with toners, characterized in that the frame member defines a plurality of concave portions (37a, 37b, 37c and 37d) to accommodate respective lower end portions of the toner containers (50a, 50b, 50c and 50d), and includes an upper frame portion located to cover a top surface of the intermediate transfer belt, wherein: - one concave portion (37a, 37b, 37c or 37d) among the plurality of the concave portions (37a, 37b, 37c and 37d) is defined by a wall portion, the wall portion defining a vent hole, - the upper frame portion defines a ventilation path located at an opposite side of the one concave portion with respect to the wall portion, the ventilation path communicating with the one concave portion (37a, 37b, 37c or 37d) via the vent hole, and - the image forming apparatus further includes a blast fan to discharge air from the ventilation path through the vent hole to a side of the one concave portion (37a, 37b, 37c or 37d) accommodating the lower end portion of the respective toner container (50a, 50b, 50c or 50d) to cool the lower end portion of the respective toner container (50a, 50b, 50c or 50d). - a frame member; - an intermediate transfer unit that includes a drive roller, a tension roller, wherein the drive roller and the tension roller are supported by the frame member, and an intermediate transfer belt stretching around the drive roller and the tension roller; - a plurality of image forming units (10a, 10b, 10c and 10d) located at a lower side of the intermediate transfer unit and located along a running direction of the intermediate transfer belt; and - a plurality of toner containers (50a, 50b, 50c and 50d) located at an upper side of the intermediate transfer belt corresponding to the respective image forming units (10a, 10b, 10c and 10d) to supply the respective image forming units (10a, 10b, 10c and 10d) with toners, - one concave portion (37a, 37b, 37c or 37d) among the plurality of the concave portions (37a, 37b, 37c and 37d) is defined by a wall portion, the wall portion defining a vent hole, - the upper frame portion defines a ventilation path located at an opposite side of the one concave portion with respect to the wall portion, the ventilation path communicating with the one concave portion (37a, 37b, 37c or 37d) via the vent hole, and - the image forming apparatus further includes a blast fan to discharge air from the ventilation path through the vent hole to a side of the one concave portion (37a, 37b, 37c or 37d) accommodating the lower end portion of the respective toner container (50a, 50b, 50c or 50d) to cool the lower end portion of the respective toner container (50a, 50b, 50c or 50d).