Bolt holes 16 are formed in a joint part 14 of a turbine housing 12, with flanged bolts 40 screwed in the bolt holes 16. A flange part 32 of a bearing housing 30 is sandwiched between bearing surfaces 44a of the flanged bolts 40 and an inner end face 14b of the joint part 14. A sealing ring 48 is interposed in an annular space s. Before the flanged bolts 40 are fastened, there is formed a height difference G equivalent to a compression allowance h for the sealing ring 48, between an outer end face 60a of the joint part 14 and a bolt receiving surface 32a of the flange part 32. The flanged bolts 40 are screwed into the bolt holes 16 until the bearing surfaces 44a make tight contact with the outer end face 60a so as to resiliently deform the sealing ring 48.