PURPOSE: To improve the rate of good valve assembly by eliminating the necessity for raising the dimensional accuracy of valve elements and the positional accuracy of assemblage by forming a dike-like protruded part on the surface of either a valve or a valve seat at their overlapped part.

CONSTITUTION: Valve members of a check valve are composed of a disk-like valve 103, an arm 104 supporting thereof and a circular ring like fixing part 105. On one side of the disk-like valve 103, a dike-like protruded part 202 is formed. As pressure acts from the side of an ink passage 101, the valve 103 is pushed up, and ink flows out through a gap between the valve 103 and a valve seat 102. As pressure acts in the inverse direction, the protruded part 202 on the valve 103 contacts with the valve seat 102 and shuts off the ink flow. At the time of flowing of ink, the gap between the dike-like protruded part 202 and the valve seat 102 is especially narrower than that between the valve 103 and the valve seat 102, therefore, the flow of ink is substantially determined by the resistance of the gap between the protruded part 202 and the valve seat 102. If the shape and dimension of the protruded part 202 are kept constant, the variation of the valve characteristics becomes smaller even if the dimensions of the valve 103 and the passage 102 of the valve seat 102 are varied and the overlapped position of the valve 103 and the passage 101 is deviated.