A blower comprises a boxy body where a body inlet and a body outlet are opposed and centrifugal blowers each of which sucks air sucked through the body inlet into the inside of the body through a centrifugal blower inlet and ejects air through a centrifugal blower outlet toward the body outlet. A maintenance opening for inspecting the inside of the body is provided in one of the surfaces forming the body other than the surface where the body inlet and the body outlet are provided. The centrifugal blowers are arranged tandem and oriented toward the maintenance opening. The difference between the ejection space distances from the respectiveoutlets of the adjacent centrifugal blowers to the centrifugal blower outlet is more than the outside diameter of the vane wheel of the centrifugal blower near the maintenance opening.