A heat pump performs a simultaneous air-conditioning and heating operation through the addition of a flow path switching apparatus. The heat pump may include a plurality of outdoor units, a plurality of indoor units, and a plurality of flow path switching apparatuses that switch a flow path between an outdoor unit and an indoor unit. A refrigerant flow path may be formed from the outdoor unit to the indoor unit via a high-pressure gas pipe. The flow path switching apparatuses may switch a flow path so that a refrigerant flow path is formed from the indoor unit to the outdoor unit via a low-pressure gas pipe. The heat pump may further include an indoor unit mode controller that is connected to the plurality of outdoor units through a liquid pipe, and which is connected to each of the plurality of flow path switching apparatuses.