Abstract: An arrangement for preventing the production of waterdrops inside a wrist watch, comprising a hollow sealed container communicating with a suction pipe having an on-off valve for a suction pump on one side and an air feed section having an on-off valve, a desiccator and a filtering material on the other side. A watch is placed in the container with the crystal of the watch loosened. Air in the container is withdrawn by the pump to decrease the pressure therein, whereupon dry air, which has been passed through a desiccator and filtering material, is suctioned into the sealed container and enters the wrist watch therein, so that dry air is thus enclosed in the watch.