To prevent the lowering of the dust removal function of an air filter through a long period of use.

In this blower, a motor 2 having several number of blades is installed through a shaft installed oin a frame 8. A circular air filter 6 having two sheets of returns 4 is screwed into a boss installed in the motor 2. A channel-shaped frame having a brush 10 is installed from over the air filter 6. The width of the return 4 is increased toward the outer periheral edge of the air filter 6. By this, a contact surface of the brush 10 with the return 4 becomes larger toward the outer peripheral edge fo the air filter 6. When both the motor 2 and the air filter 6 are rotated, dust 18 sucked from the air adheres to the surface of the air filter 6. When this adhered dust 18 increases to a specified amount, the dust is collected by the brush 10. The collected dust 18 is discharged by a centrifugal force to the outside of the brush 10 along the return 4 provided on the air filter 6.