A manufacturing method for a sliding bearing including half members, obtained by splitting a cylinder in half in a direction parallel with an axial direction, arranged in an upper and lower direction, may include a first step including forming a narrow groove extending in the circumference direction on an axial direction end of one of the half members on a lower side, on a downstream side in a rotation direction, a second step including performing shot blasting on a surface of the narrow groove; and a third step including forming coating layers on a surface of the half member. The coating layers may be formed only on an upstream-side end and a downstream-side end as parts of the narrow groove.