The utility model provides an air conditioner capable of guiding air blowing out from an outdoor unit (10) and/or an indoor unit (31) of the air conditioner, which comprises the indoor unit (31) and the outdoor unit (10), wherein air ducts (20, 40) are arranged at least on one of the air outlets (13) of the outdoor unit (10) and the indoor unit (31). By arranging the air ducts at the position of the air outlet of the outdoor unit of the air conditioner, the air outlet of the outdoor unit is extended to the position of an air outlet grid to keep an air outlet area away from an air return area so as to avoid airflow short circuit. When the outdoor unit is installed inside a small space, the air ducts are capable of extending the air outlet to a bigger space to avoid the airflow short circuit. When the air conditioner is used in a machine room with concentrated heat source devices, the air ducts arranged at the position of the air outlet of the indoor unit is capable of blowing cool air directly on the heat source devices to lower the temperature, thereby not only evidently improving temperature lowering efficiency, but also saving energy.