To provide a pressure detector capable of inhibiting the increase of the volume of a liquid phase section as well as adequately stirring the liquid in the liquid phase section.SOLUTION: The pressure detector comprises: a case C； and a diaphragm member M which partitions a liquid phase section S1 into which a liquid can be filled and a gas phase section S2 into which a gas can be filled, and which is displaceable according to the pressure of the liquid filled in the liquid phase section S1； the pressure detector detecting the pressure of the gas phase section S2 to detect the pressure of the liquid. The pressure detector further includes: an inflow port C1 comprising a projection connectable to the liquid flow passage and having a flow passage part C1a for letting the liquid flow in through an inflow opening of the liquid phase section S1； and an outflow port C2 comprising a projection connectable to the liquid flow passage and having a flow passage part C2a for letting the liquid flowed into the liquid phase section S1 flow out through an outflow opening. In the flow passage part C1a of the inflow port C1 or the flow passage part C2a of the outflow port C2, a liquid inflow direction α or a liquid outflow direction β is inclined relative to a mounting surface Q of the diaphragm member M.SELECTED DRAWING: Figure 4【課題】液相部の容量増大を抑制しつつ液相部内の液体を十分に撹拌することができる圧力検出器を提供する。【解決手段】ケースＣと、液体を充填し得る液相部Ｓ１と、気体を充填し得る気相部Ｓ２とを区画するとともに、液相部Ｓ１に充填された液体の圧力に応じて変位可能な膜部材Ｍとを具備し、気相部Ｓ２の圧力を検出することにより液体の圧力を検出する圧力検出器において、液体の流路に接続可能な突出部から成るとともに、液相部Ｓ１の流入口から液体を流入させる流路部Ｃ１ａを有した流入ポートＣ１と、液体の流路に接続可能な突出部から成るとともに、液相部Ｓ１に流入した液体を流出口から流出させる流路部Ｃ２ａを有した流出ポートＣ２とを有し、流入ポートＣ１の流路部Ｃ１ａ又は流出ポートＣ２の流路部Ｃ２ａは、その液体の流入方向α又は流出方向βが膜部材Ｍの取付面Ｑに対して傾斜して成るものである。【選択図】図４
