To provide a rainfall shielding device which can be easily installed at the time of rainfall for securing a rain-shield work space.

Air piping 1 having a number of air nozzles 2 at positions in a straight line on a tube wall are horizontally disposed to direct the air nozzles 2 sideways. Both end parts of the air piping 1 are supported by upper end parts of support posts 3. One end part of the air piping 1 is connected to a compressor 5 through a flexible connection tube 4. High pressure air 6 discharged from the compressor 5 is blown from the air nozzles 2 in the air piping 1 to form a rainshielding film 7, thereby work space 8 is formed under that.