An collective device for switching refrigerant flow arranged between an indoor device and an outdoor device is provided; which includes multiple high-pressure valves; multiple low-pressure valves; a high-pressure header; a low-pressure header; a high-pressure gas pipe connecting each high-pressure valve and the high-pressure header; and a low-pressure gas pipe connecting each low-pressure valve and the low-pressure header, wherein the multiple high-pressure valves are arranged next to each other in a first direction perpendicular to a vertical direction, the multiple low-pressure valves are arranged next to each other in the first direction, and the low-pressure valves, the low-pressure header, and the low-pressure gas pipe are arranged on one side in a second direction perpendicular to the vertical direction and the first direction with respect to the high-pressure valves, the high-pressure header, and the high-pressure gas pipe.