A flow rate regulation valve is used for a refrigeration cycle device for air conditioning. The flow rate regulation valve is constituted by: an inlet flow rate control valve connected to the inlet side of an inside evaporator and functioning in the refrigeration cycle device as an expansion valve for depressurizing and expanding a refrigerant flowing into the inside evaporator; and an outlet flow rate adjustment valve connected to the outlet side of the inside evaporator and functioning as an evaporation pressure adjustment valve for adjusting evaporation pressure in the inside evaporator to a predetermined target pressure at which frost is not formed. The flow rate regulation valve is characterized in that, when the opening of one of the inlet flow rate control valve and the outlet flow rate adjustment valve increases, the flow rate regulation valve displaces so that the opening of the other decreases.