A tension rod supporting part (14) is provided at a sub-frame front structure (10) of a front part of a front sub-frame (5); the side member (6) is disposed upward in one side and extended rearward from the tension rod supporting part (14); a rack arrangement step (A) opened downward for arranging a steering rack (55) is formed behind the tension rod supporting portion (14) and under the side member (6); and a stabilizer support part (62) is provided in the rack arrangement step (A).