To provide a movable clamping device with which a clamp main body can be surely stopped at the retreating limit position by braking it when the clamp main body is stopped at the retreating limit position.

The movable clamping device is provided with: the clamp main body 20 which is provided with a T-shaped engaging part which is engaged with a T-groove on the slide or the bolster of a press and a hydraulic cylinder 22 in a vertical attitude, and movable along the T-groove; a moving/driving means 40 by which the clamp main body 20 is moved back and forth via a chain member 41 the tip part of which is connected to the clamp main body 20 and which can enter the T-groove; a frame member 43 which is fixed to the end part of the slide or the bolster and has an extended T-groove 48 which is connected to the T-groove and a braking mechanism 80 by which braking force acts on the T-shaped engaging part from the frame member 43 when the T-shaped engaging part 21 of the clamp main body 20 is retreated into the extended T-groove 48 and the clamp main body 20 is stopped at the retreating limit position.