The present invention provides a pressure detector including: a case that can be connected to a flow path of a liquid and that can be attached to a predetermined attachment surface； and a membrane member that is attached inside the case, that defines a liquid phase part, which can be filled with the liquid in the flow path, and a gas phase part, which can be filled with gas, and that can be displaced in accordance with the pressure of the liquid filling the liquid phase part, the pressure detector detecting the pressure of the liquid in the flow path by detecting the pressure of the gas phase part. The pressure detector is characterized by having a flow-in port having a connecting part that can be connected to the flow path of the liquid and having a flow path part that allows the liquid to flow in from a flow-in hole in the liquid phase part, and a flow-out port having a connecting part that can be connected to the flow path of the liquid and having a flow path part that allows the liquid having flowed in the liquid phase part to flow out from a flow-out hole. The pressure detector is also characterized in that: the flow-out hole is formed at a position including the top part of the liquid phase part in the vertical direction in a state in which the case is attached to the predetermined attachment surface； and the flow-out port is formed so as to be inclined upward from the flow-out hole.La présente invention concerne un détecteur de pression comprenant : un boîtier qui peut être relié à un trajet d'écoulement d'un liquide et qui peut être fixé à une surface de fixation prédéterminée； et un élément de membrane qui est fixé à l'intérieur du boîtier, qui définit une partie de phase liquide, qui peut être remplie avec le liquide dans le trajet d'écoulement, et une partie de phase gazeuse, qui peut être remplie de gaz, et qui peut être déplacé en fonction de la pression du liquide remplissant la partie de phase liquide, le détecteur de pression détectant la pression du
