An air conditioner comprising: a compressor in a refrigeration cycle; a pipe connected to the compressor; and a damper for decreasing a piping vibration in the pipe, the damper comprising: a fixation part provided with a coupling hole formed therein to be coupled to the pipe, and coupled and fixed to the pipe such that the coupling hole makes contact with an outer circumferential surface of the pipe; a weight part connected to the fixation part, and provided at an inside thereof with a penetrating hole having a diameter larger than an outside diameter of the pipe formed thereto such that the pipe passes through the penetrating hole while the weight portion is spaced apart from the outer circumferential surface of the pipe; and a slitted portion formed in a slitted manner from one of the sides of the outer circumferential surfaces of the fixation part and the weight part to the coupling hole and the penetrating hole lengthways of the fixation part and the weight part; characterised in that the spacing of the weight part from the outer circumferential surface of the pipe is such that the weight part is able to move freely relative to the fixation part. a compressor in a refrigeration cycle; a pipe connected to the compressor; and a damper for decreasing a piping vibration in the pipe, the damper comprising: a fixation part provided with a coupling hole formed therein to be coupled to the pipe, and coupled and fixed to the pipe such that the coupling hole makes contact with an outer circumferential surface of the pipe; a weight part connected to the fixation part, and provided at an inside thereof with a penetrating hole having a diameter larger than an outside diameter of the pipe formed thereto such that the pipe passes through the penetrating hole while the weight portion is spaced apart from the outer circumferential surface of the pipe; and a slitted portion formed in a slitted manner from one of the sides of the outer circumferential surfaces of the fixation part and the weight part to the coupling hole and the penetrating hole lengthways of the fixation part and the weight part; characterised in that the spacing of the weight part from the outer circumferential surface of the pipe is such that the weight part is able to move freely relative to the fixation part. a fixation part provided with a coupling hole formed therein to be coupled to the pipe, and coupled and fixed to the pipe such that the coupling hole makes contact with an outer circumferential surface of the pipe; a weight part connected to the fixation part, and provided at an inside thereof with a penetrating hole having a diameter larger than an outside diameter of the pipe formed thereto such that the pipe passes through the penetrating hole while the weight portion is spaced apart from the outer circumferential surface of the pipe; and a slitted portion formed in a slitted manner from one of the sides of the outer circumferential surfaces of the fixation part and the weight part to the coupling hole and the penetrating hole lengthways of the fixation part and the weight part; characterised in that the spacing of the weight part from the outer circumferential surface of the pipe is such that the weight part is able to move freely relative to the fixation part.