An object of the present invention is to provide an image forming apparatus capable of preventing vibration of a transfer film caused from the operation of a separating device to prevent irregular density distribution and change in the hue. The image forming apparatus according to the present invention and having: a transfer-medium holding member having a transfer film for adsorbing and carrying a transfer medium and arranged such that an image is formed on the transfer medium; an internally and upwardly pushing member movably disposed on the surface of the transfer film opposite to the surface to which the transfer medium is adsorbed; a moving device for moving the internally and upwardly pushing member by a predetermined quantity so that the internally and upwardly pushing member upwardly pushes the transfer film to deform the transfer film to separate the transfer medium from the transfer film; and a preventing device for preventing vibration of the internally and upwardly pushing member.