To provide an air blasting device which can adjust the form of blown air according to its usage, and which can improve the air blasting performance to a distant place.

An air blasting device 1 is equipped with two or more guide plates 6 which guide air to the direction in which eddy current is generated to the air that is in an air blast pass 3 and fed by an air blasting means, and with an air diffuser 7 which is located at the downstream side of the guide plates 6 to blow off the air that is directed by the guide plates 6 to the outside of the air blast pass 3. In the air blasting device 1, a cross section of the nozzle of the air diffuser 7 shows that the upstream side from the narrowest part of a bottleneck 15 is formed to be a curved surface, and the down stream side is formed to be two or more continuous drill surfaces 18 and 19.