In an air conditioner having a refrigerant circuit in which a compressor, a four-way switching valve, an outdoor-side heat exchanger, an expansion valve, and an indoor-side heat exchanger are connected in succession via pipes, the interior of an enclosed vessel of a compressor, which contains a refrigerant compressing section and an electric motor, is divided airtightly into a refrigerant discharge chamber and an electric motor chamber, two refrigerant flow path pipes are provided on the electric motor chamber side, and these refrigerant flow path pipes are appropriately switched to the refrigerant discharge side and the refrigerant suction side of the compressor via the four-way switching valve, whereby one compressor can be used as an internal high pressure type or an internal low pressure type.