PURPOSE: To improve the comfortability in the cabin by providing a shifter stay while utilizing the space in the vicinity of the inner corner section between the ceiling and left/right side wall sections of a transmission case thereby reducing the size without enlarging the width of case.

CONSTITUTION: Two shifter rods 6, 7 are arranged in parallel above and below in the inner corner section R between the planar ceiling section 1c and one side wall 1b of a transmission case 1 and inserted idly into the partitions 1d, 1e. While a shifter rod 8 at the other side is arranged in parallel with said rods 6, 7 in the inner corner section L between the ceiling 1c and the upper section of the side wall 1a and inserted into the rear wall of the transmission case then L- shaped engaging arm 10 is secured to a shifter stay 6 while an oblique engaging arm 11 is secured to a shifter stay 7 where the engaging sections 10a, 11a of groove shape at the tip of said arms are approached and arranged in the vicinity of the inner corner R. Consequently the space between the case ceiling and the left/right side walls can be used to reduce the size resulting in improvement of comfortability of cabin.