A pipe unit allows refrigerant to divide or merge and includes: branch pipes; and a main pipe. The pipe unit is connected to a connection pipe, and the pipe unit and the connection pipe together form a liquid-side refrigerant channel between an outdoor unit and indoor units. The main pipe communicates with each of the branch pipes, forms a channel through which the refrigerant flows to or from each of the branch pipes, and is disposed, in an installed state, on an outdoor unit side of the branch pipes in the liquid-side refrigerant channel. The main pipe includes a first part that extends in a first direction, at least one of the branch pipes includes a second part that extends in a second direction intersecting the first direction, the first direction is horizontal in the installed state, and the second direction is vertical in the installed state.