PURPOSE: To obtain a suspension device which can ensure suitable wheel alignment by providing a pair of right and left positioning mechanisms comprising a pin member fixed to one of a sub-frame and a car body and a pin hole formed on the other thereof.

CONSTITUTION: At the time of assembling a suspension device 1 to a car body from belot, pin members 18, 23 fixed in designated positions of a side member 9 are respectively inserted through left and right pin holes 22, 25 formed on a sub-frame 8. Further, after the frame 8 is oscillated round the pin member 23 to finely adjust the position of the frame 8, six bolts 28 are tightened on a nut member 27 to fix the frame 8 in a designated position of the member 9 with good accuracy. Subsequently, the upper end portion of a shock absorber 6 is connected to the car body, and the inner ends of the respective arm portions 5a or left and right upper arms 5 are respectively connected to a supporting bracket 11 through a shaft member 12. Thus, the left and right front wheels 2 can be fixed and supported on a wheel supporting member 3 with a suitable wheel alignment.