A thrust-bearing (1) disposed to face a thrust collar provided on a rotary shaft, including: grooves (5) formed at a bearing-surface (4b); a first-groove-group (6A) constituted by a plurality of first-spiral-grooves (6) formed at an inner circumferential side of the bearing-surface (4b); a second-groove-group (7A) constituted by a plurality of second-spiral-grooves (7) formed at an outer circumferential side more than the first-groove-group (6A) and wound in the same direction as the first-spiral-groove (6); and an annular-land-section (8) formed at the side, to which a fluid is drawn, among the inner circumferential more than the first-groove-group (6A) and the outer circumferential more than the second-groove-group (7A), wherein some of the first-spiral-grooves (6) of the first-groove-group (6A) and some of the second-spiral-grooves (7) of the second-groove-group (7A) are in communication with each other via a partial-communication-section (11), at least one side of which is in partial communication with the other side.
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