A liquid path system comprising: a liquid path member that defines a screw groove of a female screw in a spiral manner from an opening in a first through hole that has an axis (Cf) directed in an upright posture, the first through hole being opened upward and being connected to a liquid path (102; 122); and a male screw member that is screwed from the opening into the liquid path member and has a screw thread that enters the screw groove, wherein a long groove that is opened at the opening and traverses the screw groove in an axial direction is formed in the female screw, an air removing passage that is connected to the long groove and leads to an air removing port that is opened toward external air and closed by a bolt, characterized in that, the liquid path system further comprises a linking member having a ring-shaped part, an arm part, and a female screw part, the ring-shaped part being overlapped with a mating surface including the aforementioned opening, the ring-shaped part being joined to the liquid path member by the male screw member, the arm part extending from the ring-shaped part, the female screw part being connected with the arm part and defining another screw groove in a spiral manner from another opening in a second through-hole that has another axis (Cs) in the upright posture, the second through-hole being opened upward and connected to the liquid path (102, 122), and an air removing bolt that is screwed from the another opening into the linking member and has the air removing passage leading to the liquid path (102, 122), another long groove being formed in the female screw part, opened at the another opening, and traversing the another screw groove in the axial direction. a liquid path member that defines a screw groove of a female screw in a spiral manner from an opening in a first through hole that has an axis (Cf) directed in an upright posture, the first through hole being opened upward and being connected to a liquid path (102; 122); and a male screw member that is screwed from the opening into the liquid path member and has a screw thread that enters the screw groove, wherein a long groove that is opened at the opening and traverses the screw groove in an axial direction is formed in the female screw, an air removing passage that is connected to the long groove and leads to an air removing port that is opened toward external air and closed by a bolt, characterized in that, the liquid path system further comprises a linking member having a ring-shaped part, an arm part, and a female screw part, the ring-shaped part being overlapped with a mating surface including the aforementioned opening, the ring-shaped part being joined to the liquid path member by the male screw member, the arm part extending from the ring-shaped part, the female screw part being connected with the arm part and defining another screw groove in a spiral manner from another opening in a second through-hole that has another axis (Cs) in the upright posture, the second through-hole being opened upward and connected to the liquid path (102, 122), and an air removing bolt that is screwed from the another opening into the linking member and has the air removing passage leading to the liquid path (102, 122), another long groove being formed in the female screw part, opened at the another opening, and traversing the another screw groove in the axial direction. a linking member having a ring-shaped part, an arm part, and a female screw part, the ring-shaped part being overlapped with a mating surface including the aforementioned opening, the ring-shaped part being joined to the liquid path member by the male screw member, the arm part extending from the ring-shaped part, the female screw part being connected with the arm part and defining another screw groove in a spiral manner from another opening in a second through-hole that has another axis (Cs) in the upright posture, the second through-hole being opened upward and connected to the liquid path (102, 122), and an air removing bolt that is screwed from the another opening into the linking member and has the air removing passage leading to the liquid path (102, 122), another long groove being formed in the female screw part, opened at the another opening, and traversing the another screw groove in the axial direction.