An air conditioner comprising: a filter assembly disposed in an air suction hole that is lengthily defined in the air conditioner in a left-right direction; and a pair of moving mechanisms configured to allow the filter assembly to move forward and backward in a direction crossing a longitudinal direction of the filter assembly, wherein the pair of moving mechanisms comprises: a motor; and a rack configured to move forward and backward by the motor; wherein the filter assembly is adapted to be withdrawn forward from the air conditioner when the motor operates, and the filter assembly is adapted to be inserted into the air conditioner when the motor operates reversely, characterized in that the air conditioner further comprises a carrier on which the filter assembly is placed, wherein the moving mechanism is connected to the carrier to allow the carrier to move forward and backward, wherein the air conditioner further comprising an accommodation body in which the air suction hole is defined, and the filter assembly is accommodated, each of front and top surfaces of the accommodation body is opened, and the filter assembly is adapted to be withdrawn forward or upward, wherein an opening through which air passes is defined in a lower portion of the accommodation body, and wherein the air conditioner further comprising a supply terminal disposed on the accommodation body, wherein the filter assembly comprises an electric filter, the electric filter comprises an electrode terminal that is connected to or disconnected from the supply terminal, and when the moving mechanism moves backward, the moving mechanism is configured to allow the carrier to move backward to a connection position at which the electrode terminal is connected to the supply terminal. a filter assembly disposed in an air suction hole that is lengthily defined in the air conditioner in a left-right direction; and a pair of moving mechanisms configured to allow the filter assembly to move forward and backward in a direction crossing a longitudinal direction of the filter assembly, wherein the pair of moving mechanisms comprises: a motor; and a rack configured to move forward and backward by the motor; a motor; and a rack configured to move forward and backward by the motor; wherein the filter assembly is adapted to be withdrawn forward from the air conditioner when the motor operates, and the filter assembly is adapted to be inserted into the air conditioner when the motor operates reversely, characterized in that the air conditioner further comprises a carrier on which the filter assembly is placed, wherein the moving mechanism is connected to the carrier to allow the carrier to move forward and backward, wherein the air conditioner further comprising an accommodation body in which the air suction hole is defined, and the filter assembly is accommodated, each of front and top surfaces of the accommodation body is opened, and the filter assembly is adapted to be withdrawn forward or upward, wherein an opening through which air passes is defined in a lower portion of the accommodation body, and wherein the air conditioner further comprising a supply terminal disposed on the accommodation body, wherein the filter assembly comprises an electric filter, the electric filter comprises an electrode terminal that is connected to or disconnected from the supply terminal, and when the moving mechanism moves backward, the moving mechanism is configured to allow the carrier to move backward to a connection position at which the electrode terminal is connected to the supply terminal.