An image forming apparatus including a medium storage portion, a supply roller, a conveyance roller, a drive device and a transmission device is provided. The supply roller is rotary driven in a forward direction as a rotating direction to convey the recording mediums to a position for image formation, thereby to supply the abutting uppermost recording medium to a conveyance path. The conveyance roller is rotary driven in a forward direction as a rotating direction to convey the recording mediums to a position for image formation, thereby to allow passage of the uppermost recording medium conveyed by the supply roller. In the image forming apparatus, a conveyance speed of the recording medium by the conveyance roller is adapted to be faster than a conveyance speed of the recording medium by the supply roller.