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 (A1) having a first thickness (T1) and a second area (A2) having a second thickness (T2) thinner than the first thickness (T1), the second area (A2) has a stepped portion (A12) from the first area (A1) and is disposed downstream of the first area (A1) in the air flow direction, wherein the blade tip faces the second area (A2) 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 (A1) having a first thickness (T1) and a second area (A2) having a second thickness (T2) thinner than the first thickness (T1), the second area (A2) has a stepped portion (A12) from the first area (A1) and is disposed downstream of the first area (A1) in the air flow direction, wherein the blade tip faces the second area (A2) 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 (A1) having a first thickness (T1) and a second area (A2) having a second thickness (T2) thinner than the first thickness (T1), the second area (A2) has a stepped portion (A12) from the first area (A1) and is disposed downstream of the first area (A1) in the air flow direction, wherein the blade tip faces the second area (A2) 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 . <EOS>