A blower 10 includes: a housing 11 having an intake port 16 and a flow passage 22 that communicates with a discharge port 17 an impeller 13 disposed in the housing 11 so that the front surface thereof faces the intake port 16 and a partitioning member 15 that is disposed toward the rear surface of the impeller 13 to partition the inside of the housing 11 into a space 21 in which the impeller 13 is disposed and the flow passage 22. The partitioning member 15 forms a slit d, which has a width w of 1.0 mm or less and extends along the inner peripheral surface of the housing 11, between the partitioning member 15 and the inner peripheral surface of the housing 11.