finely adjusted to within a desired range in every scroll compressor the alignment of fixed scroll 1 and orbiting scroll 2 in a plane perpendicular to the x axis is defined by an alignment of fixed scroll 1 and front housing 6 in a plane perpendicular to the x axis in this invention of a scroll type fluid displacement apparatus each of smaller diameter holes 1 b and larger diameter holes 6 a faces and corresponds to one of the other when fixed scroll 1 and front housing 6 are assembled a pin is used to insert into smaller diameter hole 1 b and larger diameter hole 6 a the pin has a smaller diameter portion which fits smaller diameter hole 1 b and a larger diameter portion which fits larger diameter hole 6 a each such pin results in a different alignment of the smaller diameter portion and larger diameter portion as shown in fig2 a 2 e by preparing a plurality of pins which have a different alignment of the smaller diameter portion and larger diameter portion and by selecting an appropriate pin therefrom the alignment of smaller diameter hole 1 b and larger diameter hole 6 a in a plane perpendicular to the x axis may be finely adjusted therefore an alignment of fixed scroll 1 and front housing 6 in a.