A
fluid pressure pulsation
damper mechanism comprising: a
metal damper having two
metal diaphragms joined together with a
hermetic seal for forming a sealed spacing filled with a gas between the two
metal diaphragms, an edge part at which are overlapped along outer peripheries thereof; a main body having a
damper housing in which the metal damper is accommodated; and a cover attached to the main body to cover the damper housing and isolate the damper housing from an outside air, the metal damper being held between the cover and the main body; wherein the cover is further comprising: a metal plate for making the cover, a
peripheral edge of the cover being joined to the main body, a plurality of inner convex curved parts extending toward the main body and a plurality of outer convex curved parts extending in a direction away from the main body, and a plurality of the inner convex curved parts and a plurality of the outer convex parts being disposed alternately inside the
peripheral edge of the cover at which the cover is joined to the main body; wherein the cover is attached to the main body, ends of the plurality of inner convex curved parts touch one side of the edge part of the metal damper, which are outwardly formed in radial directions of a part including the sealed spacing in the metal damper; and the metal damper is held between the cover and a metal damper holding part of a holding member placed on the main body.