A fan comprising: a fan motor for generating a suction force for sucking air having: a motor housing, a rotating shaft, a rotor mounted on the rotating shaft and a stator disposed within the motor housing to surround the rotor; an impeller having at least one blade formed on an outer surface of a hub connected to the rotating shaft, the blade including a blade tip positioned at the outermost side with respect to a central axis of the hub and the blade is made of a non-metal material; and an impeller cover coupled to the motor housing, configured to surround an outer circumference of the impeller and having an air suction port formed therein; wherein the impeller cover includes: a shroud with an inner diameter that expands in an air flow direction; and wherein a maximum diameter of the impeller is larger than a diameter of the air suction port, characterized in that the impeller cover further includes: a non-metallic coating layer coated on an inner circumferential surface of the shroud wherein the non-metallic coating layer includes a first area having a first thickness and a second area having a second thickness thinner than the first thickness, the second area has a stepped portion from the first area and is disposed downstream of the first area in the air flow direction, wherein the blade tip faces the second area in a radial direction of the impeller, and wherein the non-metallic coating layer is a soft material with a strength which is 50% or less of the strength of the blade. a motor housing, a rotating shaft, a rotor mounted on the rotating shaft and a stator disposed within the motor housing to surround the rotor; an impeller having at least one blade formed on an outer surface of a hub connected to the rotating shaft, the blade including a blade tip positioned at the outermost side with respect to a central axis of the hub and the blade is made of a non-metal material; and an impeller cover coupled to the motor housing, configured to surround an outer circumference of the impeller and having an air suction port formed therein; wherein the impeller cover includes: a shroud with an inner diameter that expands in an air flow direction; and wherein a maximum diameter of the impeller is larger than a diameter of the air suction port, a shroud with an inner diameter that expands in an air flow direction; and wherein a maximum diameter of the impeller is larger than a diameter of the air suction port, characterized in that the impeller cover further includes: a non-metallic coating layer coated on an inner circumferential surface of the shroud wherein the non-metallic coating layer includes a first area having a first thickness and a second area having a second thickness thinner than the first thickness, the second area has a stepped portion from the first area and is disposed downstream of the first area in the air flow direction, wherein the blade tip faces the second area in a radial direction of the impeller, and wherein the non-metallic coating layer is a soft material with a strength which is 50% or less of the strength of the blade. a non-metallic coating layer coated on an inner circumferential surface of the shroud wherein the non-metallic coating layer includes a first area having a first thickness and a second area having a second thickness thinner than the first thickness, the second area has a stepped portion from the first area and is disposed downstream of the first area in the air flow direction, wherein the blade tip faces the second area in a radial direction of the impeller, and wherein the non-metallic coating layer is a soft material with a strength which is 50% or less of the strength of the blade.