An image forming apparatus includes an image holding member, an exposing device, a developing device, a transfer device, a fixing device, a container mounting portion demountably mounted with a toner container, a toner supply unit supplying the toner to the developing device from the toner container, a first estimation unit estimating an amount of toner used on the basis of the image data, a second estimation unit estimating the amount of toner used on the basis of a toner supplying operation of the toner supply unit, and an emptiness determining unit determining emptiness of the toner container on the basis of only the amount of toner used estimated by the first estimation unit in a first state and both the amounts of toner used estimated by the first and second estimation units in a second state.