<p>An oil pump has: a base part (1) having a working chamber (11); and a rotor (3) provided rotatably in the working chamber (11). The base part (1) is configured by a plurality of split bodies (13,18). At least one split body (18) (rear housing) out of the plurality of split bodies (13,18) is made of aluminum alloy, and on which an opposed sliding surface (180) made of a ceramic film (185) is formed. The ceramic film (185) of the opposed sliding surface (180) has a hardness of approximately Hv 500 to 1100 and a surface roughness of approximately 2 to 8 micrometers, and contains ± - alumina and zirconia.</p>
