The aim of the invention is to obtain a cost-effective solution for providing a microsystem with bearings, which have sufficiently high precision and long-term stress resistance. The invention proposes a method for manufacturing, adapting or adjusting a bearing portion in a fluidal microcomponent (M) comprising a stator (30) and a rotor (40,2). Said rotor is rotatably supported on the at least one bearing portion (L10,L11) relative to said stator. Said rotor (40,2) is rotatably supported by a sleeve (10, 11) inserted into said stator (30), for forming said bearing portion, the at least one sleeve being inserted in said stator as a bearing sleeve and comprising an inner surface and an outer surface (10i, 10a; 11i, 11a). Before being inserted in said stator, said bearing sleeve (10, 11) is a separate bearing component comprising an inner surface (10i, 11i) as an inner bearing surface, which is mechanically micro-finished before being inserted into said stator (30). The outer surface (10a, 11a) of said bearing component (10, 11) is mechanically permanently connected with said stator (30).