A powder replenisher comprising: a powder storage to store powder; a powder replenishment container to be replenished with the powder; a variable capacity portion having a capacity that is variable; a pressure adjuster to increase and decrease operating pressure applied to the variable capacity portion, the pressure adjuster to change the capacity of the variable capacity portion to transport the powder; a powder measuring instrument to measure an amount of the powder that replenishes the powder replenishment container; an operating pressure detector to detect the operating pressure; and a controller operatively connected to the pressure adjuster, the powder measuring instrument, and the operating pressure detector, the controller to: perform a precise replenishing mode in which, after the controller determines that the powder replenishment container is replenished with the powder in a predetermined amount, while the controller controls the powder measuring instrument to measure the amount of the powder inside the powder replenishment container, the controller controls the pressure adjuster to replenish the powder replenishment container with the powder in a target amount; and control the pressure adjuster to replenish the powder replenishment container with the powder while the controller controls the pressure adjuster based on the operating pressure detected by the operating pressure detector in the precise replenishing mode. a powder storage to store powder; a powder replenishment container to be replenished with the powder; a variable capacity portion having a capacity that is variable; a pressure adjuster to increase and decrease operating pressure applied to the variable capacity portion, the pressure adjuster to change the capacity of the variable capacity portion to transport the powder; a powder measuring instrument to measure an amount of the powder that replenishes the powder replenishment container; an operating pressure detector to detect the operating pressure; and a controller operatively connected to the pressure adjuster, the powder measuring instrument, and the operating pressure detector, the controller to: perform a precise replenishing mode in which, after the controller determines that the powder replenishment container is replenished with the powder in a predetermined amount, while the controller controls the powder measuring instrument to measure the amount of the powder inside the powder replenishment container, the controller controls the pressure adjuster to replenish the powder replenishment container with the powder in a target amount; and control the pressure adjuster to replenish the powder replenishment container with the powder while the controller controls the pressure adjuster based on the operating pressure detected by the operating pressure detector in the precise replenishing mode. perform a precise replenishing mode in which, after the controller determines that the powder replenishment container is replenished with the powder in a predetermined amount, while the controller controls the powder measuring instrument to measure the amount of the powder inside the powder replenishment container, the controller controls the pressure adjuster to replenish the powder replenishment container with the powder in a target amount; and control the pressure adjuster to replenish the powder replenishment container with the powder while the controller controls the pressure adjuster based on the operating pressure detected by the operating pressure detector in the precise replenishing mode.