PURPOSE: To save time and trouble by executing surface preparation action and remover application action to a formwork without requiring any hand.

CONSTITUTION: The formwork maintenance device has a frame 23 which is provided thereon with an electromagnet 25a fixable on the formwork along the surface of the frame 23 and also a moving unit 26 engaging with the frame 23 and freely movable along the frame 23 in the arrow marked directions E, F. The moving unit 26 is provided with a rotary brush 45, which is capable of making a surface preparation action to the formwork, a vent pipe 56 and dust collection device and also provided with a nozzle 50, which is capable of injecting remover on the surface side of the formwork, a communication pipe 51, a manifold 52 and a supply pipe 53.