A valve device comprising: a case comprising an open lower portion and an accommodation space formed therein; a base plate to cover the open lower portion of the case; an inlet pipe connected to the base plate and formed to introduce a refrigerant to the accommodation space therethrough; a boss installed to the base plate and comprising a plurality of refrigerant inlet and outlet holes through which the introduced refrigerant from the accommodation space is introduced and discharged; a plurality of inlet and outlet pipes respectively connected to the plurality of refrigerant inlet and outlet holes, and through which the refrigerant is introduced from the boss or discharged to the boss; and a pad comprising an open cavity formed therein to selectively open one refrigerant inlet and outlet hole (83, 84, 85, 86) among the plurality of refrigerant inlet and outlet holes, and a connection cavity formed therein to selectively connect two refrigerant inlet and outlet holes (83, 84, 85, 86) among the plurality of refrigerant inlet and outlet holes, wherein the open cavity comprises a first region formed on one side of the open cavity and a second region formed on an other side of the open cavity and provided at a position rotated 45 degrees clockwise from the first region with respect to a center of the pad; the first region is a portion adjacent to a left end and the second region is a portion adjacent to a right end when the pad is viewed from the top; and wherein the open cavity has a size that allows the first region or the second region to selectively open one refrigerant inlet and outlet hole (83, 84, 85, 86) among the plurality of refrigerant inlet and outlet holes. a case comprising an open lower portion and an accommodation space formed therein; a base plate to cover the open lower portion of the case; an inlet pipe connected to the base plate and formed to introduce a refrigerant to the accommodation space therethrough; a boss installed to the base plate and comprising a plurality of refrigerant inlet and outlet holes through which the introduced refrigerant from the accommodation space is introduced and discharged; a plurality of inlet and outlet pipes respectively connected to the plurality of refrigerant inlet and outlet holes, and through which the refrigerant is introduced from the boss or discharged to the boss; and a pad comprising an open cavity formed therein to selectively open one refrigerant inlet and outlet hole (83, 84, 85, 86) among the plurality of refrigerant inlet and outlet holes, and a connection cavity formed therein to selectively connect two refrigerant inlet and outlet holes (83, 84, 85, 86) among the plurality of refrigerant inlet and outlet holes, wherein the open cavity comprises a first region formed on one side of the open cavity and a second region formed on an other side of the open cavity and provided at a position rotated 45 degrees clockwise from the first region with respect to a center of the pad; the first region is a portion adjacent to a left end and the second region is a portion adjacent to a right end when the pad is viewed from the top; and wherein the open cavity has a size that allows the first region or the second region to selectively open one refrigerant inlet and outlet hole (83, 84, 85, 86) among the plurality of refrigerant inlet and outlet holes.