A throttle device comprising: a tube body provided in a ductwork supplying a refrigerant, the tube body having open end portions provided at two ends and communicating with the ductwork; a valve seat disposed inside the tube body and having a valve port; a needle member is provided to be capable of approaching or moving away from the valve port of the valve seat, and having a tapered portion having a taper angle 2θ and configured to control an aperture area of the valve port; adjusting means (12, 16) for adjusting a prescribed amount of lift L' of the tapered portion of the needle member representing an amount of lift of the needle member at the maximum differential pressure which is equal to any of 1.93 MPa, 1.98 MPa, 1.2 MPa and 0.82 MPa when R410a, R32, R22 and R134a is the respective refrigerant, the maximum differential pressure assumed in pressure of the refrigerant between the open end portions of the tube body at the time of normal operation on the assumption of using various refrigerants, on the basis of an inside diameter of the valve port, the taper angle 2θ, and a spring constant of a coil spring of the adjusting means (12, 16), wherein the adjusting means (12, 16) comprises: said coil spring configured to bias the tapered portion of the needle member in a direction to approach the valve port; and an adjustment screw configured to adjust an amount of deflection of the coil spring, and characterised in that a maximum insertion length X is equal to a value expressed by the prescribed amount of lift L'×cos 2 θ, the maximum insertion length X being a length of the tapered portion of the needle member inserted into the valve port when the tapered portion makes the aperture area of the valve port nearly zero. a tube body provided in a ductwork supplying a refrigerant, the tube body having open end portions provided at two ends and communicating with the ductwork; a valve seat disposed inside the tube body and having a valve port; a needle member is provided to be capable of approaching or moving away from the valve port of the valve seat, and having a tapered portion having a taper angle 2θ and configured to control an aperture area of the valve port; adjusting means (12, 16) for adjusting a prescribed amount of lift L' of the tapered portion of the needle member representing an amount of lift of the needle member at the maximum differential pressure which is equal to any of 1.93 MPa, 1.98 MPa, 1.2 MPa and 0.82 MPa when R410a, R32, R22 and R134a is the respective refrigerant, the maximum differential pressure assumed in pressure of the refrigerant between the open end portions of the tube body at the time of normal operation on the assumption of using various refrigerants, on the basis of an inside diameter of the valve port, the taper angle 2θ, and a spring constant of a coil spring of the adjusting means (12, 16), wherein the adjusting means (12, 16) comprises: said coil spring configured to bias the tapered portion of the needle member in a direction to approach the valve port; and an adjustment screw configured to adjust an amount of deflection of the coil spring, and characterised in that a maximum insertion length X is equal to a value expressed by the prescribed amount of lift L'×cos 2 θ, the maximum insertion length X being a length of the tapered portion of the needle member inserted into the valve port when the tapered portion makes the aperture area of the valve port nearly zero. said coil spring configured to bias the tapered portion of the needle member in a direction to approach the valve port; and an adjustment screw configured to adjust an amount of deflection of the coil spring, and characterised in that a maximum insertion length X is equal to a value expressed by the prescribed amount of lift L'×cos 2 θ, the maximum insertion length X being a length of the tapered portion of the needle member inserted into the valve port when the tapered portion makes the aperture area of the valve port nearly zero.