There is provided a mammography apparatus capable of delivering a greater load when a breast is released than a load delivered when the breast is compressed by a compression paddle. A mammography apparatus includes a main body having an X-ray generating unit and an X-ray detecting unit, wherein the main body includes a ball screw extending in a vertical direction, a gear unit configured to receive a driving force and be vertically movable along the ball screw, a compression paddle connected to the gear unit and configured to move down in a direction in which the ball screw extends to compress a subject, a handgrip configured to manipulate the compression paddle to be vertically movable, and a power transmission device configured to deliver a driving force delivered from the handgrip to the gear unit, and the power transmission device includes a torque limiter configured to deliver a restricted driving force to the gear unit and a one-way clutch configured to deliver a driving force only when the gear unit moves in one direction.
