PROBLEM TO BE SOLVED: To provide a clinical thermometer capable of preventing damage to an eardrum when inserting a temperature sensor into an ear canal and keeping a fixed distance between the eardrum and a tip of the temperature sensor inserted in the ear canal.SOLUTION: A clinical thermometer 1 is for measuring body temperature of a subject, which may be a human or animal, and comprises; a temperature sensor 2 configured to be inserted into an ear canal of the subject to measure temperature in the ear canal or of an eardrum of the subject; an insertion member 3 that holds the temperature sensor 2 on a front-end side thereof and has a diameter smaller than that of the ear canal; a cuff 3a fixed to the insertion member 3; a pump 11 configured to supply fluid into the cuff 3a; a supply path 31 that connects the pump 11 to the cuff 3a; and a stopper 10 coupled to the insertion member 3 on a side opposite the temperature sensor 2 and having a size larger than the inner diameter of the ear canal viewing from a direction in which the temperature sensor 2 is inserted into the ear canal.SELECTED DRAWING: Figure 1【課題】温度センサを外耳道内に挿入する際に鼓膜などの損傷を防止することができ、また、外耳道内へ挿入された温度センサの先端と鼓膜との間の距離を一定に保つことを容易にする体温計を提供する。【解決手段】ヒトまたは動物である被験体の体温を測定するための体温計1であって、被験体の外耳道の内部に挿入され、外耳道の内部の温度または被験体の鼓膜の温度を測定する温度センサ2と、温度センサ2を先端側に保持する、外耳道の径よりも細い挿入部材3と、挿入部材3に固定されたカフ3aと、カフ3aの内部に流体を供給するポンプ11と、ポンプ11とカフ3aとを接続する供給経路31と、挿入部材3の温度センサ2と反対側に連結したストッパ10を備え、ストッパ10は、外耳道への温度センサ2の挿入方向から見て、外耳道の内径よりも大きいことを特徴とする、体温計。【選択図】図1