A compressor for an apparatus including a refrigeration cycle, the compressor comprising: a piston which reciprocates in a cylinder; a linear motor configured to provide a driving force to move the piston; and a compressor controller configured to sense a motor current and a motor voltage of the linear motor and detect information related to a load of the apparatus, wherein the compressor controller is further configured to: calculate a stroke of the piston based on the motor current and a motor voltage of the liner motor; calculate a phase difference between the motor current and the stroke; compare (S240, S310, S410, S510, S610, S710) the calculated phase difference with a reference phase difference; and control (S250, S320, S330, S340, S350, S370, S380, S420, S430, S520, S530, S620a, S620b, S730, S740, S750) a cooling capacity of the linear compressor according to a result of said comparison with respect to phase difference, characterized in that the compressor controller is further configured to: detect information related to a driving rate of the linear compressor; and change (S570, S580, S590) the reference phase difference based on the detected driving rate. a piston which reciprocates in a cylinder; a linear motor configured to provide a driving force to move the piston; and a compressor controller configured to sense a motor current and a motor voltage of the linear motor and detect information related to a load of the apparatus, wherein the compressor controller is further configured to: calculate a stroke of the piston based on the motor current and a motor voltage of the liner motor; calculate a phase difference between the motor current and the stroke; compare (S240, S310, S410, S510, S610, S710) the calculated phase difference with a reference phase difference; and control (S250, S320, S330, S340, S350, S370, S380, S420, S430, S520, S530, S620a, S620b, S730, S740, S750) a cooling capacity of the linear compressor according to a result of said comparison with respect to phase difference, characterized in that the compressor controller is further configured to: detect information related to a driving rate of the linear compressor; and change (S570, S580, S590) the reference phase difference based on the detected driving rate. calculate a stroke of the piston based on the motor current and a motor voltage of the liner motor; calculate a phase difference between the motor current and the stroke; compare (S240, S310, S410, S510, S610, S710) the calculated phase difference with a reference phase difference; and control (S250, S320, S330, S340, S350, S370, S380, S420, S430, S520, S530, S620a, S620b, S730, S740, S750) a cooling capacity of the linear compressor according to a result of said comparison with respect to phase difference, characterized in that the compressor controller is further configured to: detect information related to a driving rate of the linear compressor; and change (S570, S580, S590) the reference phase difference based on the detected driving rate. detect information related to a driving rate of the linear compressor; and change (S570, S580, S590) the reference phase difference based on the detected driving rate.