An air conditioner comprising: a first sensor that is attached to a wall-mounted indoor unit and can detect the presence or absence of a person in a first detectable region; a second sensor that is attached to the indoor unit and can detect the presence or absence of a person in a second detectable region; a masking member; a control unit that controls operation in accordance with the presence or absence of a person that has been detected by the first sensor and the second sensor; and a horizontal flap that is pushed out frontward of the indoor unit during operation and changes the blow-out direction of conditioned air in an up and down direction, wherein the first sensor detects the presence or absence of a person in a left direction as seen from the indoor unit, the second sensor detects the presence or absence of a person in a right direction as seen from the indoor unit, the masking member masks the first detectable region to thereby limit the first detectable region to a first detection region and masks the second detectable region to thereby limit the second detectable region to a second detection region, the masking member is a single member that masks both the first detectable region and the second detectable region and limits a boundary on the right side of the first detectable region and limits a boundary on the left side of the second detectable region as seen from the indoor unit, and the masking member masks the first detectable region and the second detectable region in such a way that the horizontal flap during operation does not enter the first detection region and the second detection region, and limits a lower boundary of the first detectable region and the second detectable region. a first sensor that is attached to a wall-mounted indoor unit and can detect the presence or absence of a person in a first detectable region; a second sensor that is attached to the indoor unit and can detect the presence or absence of a person in a second detectable region; a masking member; a control unit that controls operation in accordance with the presence or absence of a person that has been detected by the first sensor and the second sensor; and a horizontal flap that is pushed out frontward of the indoor unit during operation and changes the blow-out direction of conditioned air in an up and down direction, wherein the first sensor detects the presence or absence of a person in a left direction as seen from the indoor unit, the second sensor detects the presence or absence of a person in a right direction as seen from the indoor unit, the masking member masks the first detectable region to thereby limit the first detectable region to a first detection region and masks the second detectable region to thereby limit the second detectable region to a second detection region, the masking member is a single member that masks both the first detectable region and the second detectable region and limits a boundary on the right side of the first detectable region and limits a boundary on the left side of the second detectable region as seen from the indoor unit, and the masking member masks the first detectable region and the second detectable region in such a way that the horizontal flap during operation does not enter the first detection region and the second detection region, and limits a lower boundary of the first detectable region and the second detectable region.