operation surface of the operation panel 9 39 and the first frame member 5 39 so that the second frame member 8 mounted along the front peripheral margin 9a 39 appears to be continuous from the first frame member 5 39 in fig6 b grooves 5a 39 associated with the projections 3 of the upper case 2 are provided at the back of the first frame member 5 39 however they are not required if the operation panel 9 39 is fixed to the lower case 12 in the aforegoing arrangements the first frame member 5 is provided in the upper half of the operation panel 9 whereas the second frame member 8 has its seat in the lower half of same however the invention is not limited to this fig7 shows an arrangement in which the second frame member 8 has its seat in the upper half of the operation panel 9 fig8 shows an arrangement of car electronic device 1 in which the second frame member 8 has its seat in the lower half of the operation panel 9 the cover member 8b of the second frame member 8 has a projection 15 defining a frontwardly descending slope on one of its surfaces facing frontwardly when the second frame member 8 is held in its sitting configuration the projection 15 has an engage hole 15a opening at the bottom thereof in the aligned configuration of the second frame member 8 by inserting a tool 16 in the engage hole 15a and pulling the tool 16 forwardly the second frame member 8 is readily raised up from its aligned position closely contacting the front peripheral margin.