A sliding bearing 1 is formed cylindrically of a pair of half bearings 11 and 12. A dust pocket 4 formed of a recess part is formed in the inner peripheral edges of joining surfaces 11A and 12A of the half bearings 11 and 12, and foreign-substance discharge grooves 5 and 5′ are formed in a sliding surface 3 continuing from the dust pocket 4. When lubricant oil is supplied to the dust pocket 4, foreign substances 6 mixed in the lubricant oil are caught by the dust pocket 4 and then, discharged efficiently to the outside of the sliding bearing 1 through the foreign-substance discharge grooves 5 and 5′. The sliding bearing 1 having favorable foreign-substance discharging performances can be provided.