To easily and positively identify a narcotic by changing temperature so that one portion of the narcotic changes from a first assembly to a second assembly state and detecting a transfer temperature where transfer occurs.

An anesthetizing device is provided with a device 66 for identifying a connected narcotic and the position of the device 66 can be changed depending on whether a liquid narcotic or gas-shaped narcotic is identified. The device 66 is provided with a tube 70 and a vaporized anesthetic gas passes through the tube 70 and then is supplied in an arrow direction. The passing gas has a known pressure and flow characteristics and is adjusted by the gas mixer of the anesthetizing device. A heat element 74 is arranged at the tube 70 to change the temperature of a surface 78 of the tube 70. The heat element 74 is controlled by a temperature regulator 76. The capacity between two conductors 72A and 72B changes when the narcotic is condensed on the surface 78 and the change is measured by a capacitance meter 80, thus specifying an anesthetic gas from the condensation temperature.