Thrust bearing and bearing device

A thrust bearing having a slide surface in a circular ring shape or a half-split circular ring shape, the thrust bearing comprising:

• a planar portion having a plane on the slide surface where a wall thickness is constant;
• a taper portion having a tapered surface on the slide surface where a wall thickness gradually decreases from an end portion of the planar portion toward a prescribed sliding direction;
• and
• a pocket portion on the slide surface, the pocket portion comprising:
• a bottom surface in which a wall thickness is thinner than a thinnest portion of the taper portion;
• a first side surface formed on the side of the taper portion;
• and
• a second side surface formed on a side opposed to the first side surface,
• wherein the planar portion, the taper portion and the pocket portion are disposed in order along the sliding direction on the slide surface,
• wherein a depth from the plane of the planar portion to the thinnest portion of the taper portion is between 10 μm and 80 μm,
• wherein a first angle that is an angle between a virtual surface obtained by extending the bottom surface and the second side surface is between 90° and 120°, and a second angle that is an angle between a virtual surface obtained by extending the first side surface and the tapered surface is between 60° and 120°.