PURPOSE: To make the fitting work of electronic parts provided with a rotary mobile section to the inside of an electronic equipment case easier.

CONSTITUTION: After electronic parts are positioned in an electronic equipment case 9, a rotation adjusting shaft 4 is inserted into the case 9 from a through hole 10 provided through the case 9 and an engaging section 3 at the front end of the shaft 4 is engaged with the engaging recessed section 6 of a rotary mobile section 5. At the same time, a seal 11 having an opening window 12 which is a little smaller in diameter than the hole 10 is stuck to the hole 10.