A front suction/discharge type outdoor unit for an air conditioner, comprising: an outdoor unit casing having a front surface unit opened to be linked to the outside of a building, both side units (12a, 12b) formed at both ends of the front surface unit, a rear surface unit formed to face the front surface unit, a bottom surface unit formed at the lower ends of the front surface unit and the rear surface unit, and a top surface unit formed at the upper ends of the front surface unit and the rear surface unit, the inside of the outdoor unit casing being separated from the inside of the building by the both side units (12a, 12b), the rear surface unit, the bottom surface unit and the top surface unit; a compressor for compressing a refrigerant gas supplied from an indoor unit to the outdoor unit casing; an air-cooled condenser installed in the outdoor unit casing, for condensing the refrigerant gas supplied from the compressor; and a cooling fan for sucking outdoor air from the outside of the building through the front surface unit and the air-cooled condenser, and discharging air heat-exchanged in the air-cooled condenser to the outside of the building through the front surface unit; whereby said air cooled condenser has a U-shaped cross section and comprises at least one rounded unit (30a, 30b); characterized in that said air-cooled condenser is disposed to face the both side units (12a, 12b) at a predetermined distance and to face the front surface unit; a top cover is installed at the upper side of a space formed between the air-cooled condenser and the surfaces of the outdoor unit casing facing the air-cooled condenser, for inducing outdoor air sucked from the outside of the building through the front surface unit to the space; a radius of the rounded unit (30a, 30b) of the air-cooled condenser is at least twice as large as a predetermined distance of the space between the air-cooled condenser and the both side units (12a, 12b) of the outdoor unit casing. an outdoor unit casing having a front surface unit opened to be linked to the outside of a building, both side units (12a, 12b) formed at both ends of the front surface unit, a rear surface unit formed to face the front surface unit, a bottom surface unit formed at the lower ends of the front surface unit and the rear surface unit, and a top surface unit formed at the upper ends of the front surface unit and the rear surface unit, the inside of the outdoor unit casing being separated from the inside of the building by the both side units (12a, 12b), the rear surface unit, the bottom surface unit and the top surface unit; a compressor for compressing a refrigerant gas supplied from an indoor unit to the outdoor unit casing; an air-cooled condenser installed in the outdoor unit casing, for condensing the refrigerant gas supplied from the compressor; and a cooling fan for sucking outdoor air from the outside of the building through the front surface unit and the air-cooled condenser, and discharging air heat-exchanged in the air-cooled condenser to the outside of the building through the front surface unit; whereby said air cooled condenser has a U-shaped cross section and comprises at least one rounded unit (30a, 30b); characterized in that said air-cooled condenser is disposed to face the both side units (12a, 12b) at a predetermined distance and to face the front surface unit; a top cover is installed at the upper side of a space formed between the air-cooled condenser and the surfaces of the outdoor unit casing facing the air-cooled condenser, for inducing outdoor air sucked from the outside of the building through the front surface unit to the space; a radius of the rounded unit (30a, 30b) of the air-cooled condenser is at least twice as large as a predetermined distance of the space between the air-cooled condenser and the both side units (12a, 12b) of the outdoor unit casing.