An air conditioner comprising: a casing that includes a suction opening (8 to 11) through which air that is taken in from indoors passes and a blowout opening (6, 7) through which air that is blown out to the indoors passes; a filter (3a to 3d) that is disposed downstream of the suction opening (8 to 11) and transmits air; a heat exchanger that is disposed facing the filter (3a to 3d) downstream of the filter (3a to 3d) and performs heat exchange with air that passes through the heat exchanger; a centrifugal fan that is disposed downstream of the heat exchanger and generates a flow of air that is sucked in from the suction opening (8 to 11) and is blown out from the blowout opening (6, 7); and a blowout passage (P2, P3) that includes an air introduction opening that is disposed facing the heat exchanger downstream of the heat exchanger and guide air from the air introduction opening to the blowout opening (6, 7), wherein the filter (3a to 3d) has an outer shape that is slanted with respect to the heat exchanger, characterized in that the casing further includes a panel portion that is disposed on front surface of the casing, the suction opening (8 to 11) is disposed around the panel portion, the filter (3a to 3d) is disposed facing the panel portion, and the surface of the filter (3a to 3d) on the panel portion side has a shape that slants with respect to the heat exchanger,wherein the flow velocity of the air that proceeds along the inner surface of the flat panel portion, and the direction of the flow can be changed as a result of air coming into contact with the slanted surfaces of the filter. a casing that includes a suction opening (8 to 11) through which air that is taken in from indoors passes and a blowout opening (6, 7) through which air that is blown out to the indoors passes; a filter (3a to 3d) that is disposed downstream of the suction opening (8 to 11) and transmits air; a heat exchanger that is disposed facing the filter (3a to 3d) downstream of the filter (3a to 3d) and performs heat exchange with air that passes through the heat exchanger; a centrifugal fan that is disposed downstream of the heat exchanger and generates a flow of air that is sucked in from the suction opening (8 to 11) and is blown out from the blowout opening (6, 7); and a blowout passage (P2, P3) that includes an air introduction opening that is disposed facing the heat exchanger downstream of the heat exchanger and guide air from the air introduction opening to the blowout opening (6, 7), wherein the filter (3a to 3d) has an outer shape that is slanted with respect to the heat exchanger, characterized in that the casing further includes a panel portion that is disposed on front surface of the casing, the suction opening (8 to 11) is disposed around the panel portion, the filter (3a to 3d) is disposed facing the panel portion, and the surface of the filter (3a to 3d) on the panel portion side has a shape that slants with respect to the heat exchanger,wherein the flow velocity of the air that proceeds along the inner surface of the flat panel portion, and the direction of the flow can be changed as a result of air coming into contact with the slanted surfaces of the filter.