PURPOSE: To secure speedy lifting performance and safety by laying out an upper part ladder and a lower part ladder, which are in a working sate, on a straight line in terms of a ceiling housing type ladder device which forms a working state and a housing state with a motor-drive means.

CONSTITUTION: A cover 2 is pivoted with one end of the bottom of a housing frame 1 installed to a ceiling opening in such a fashion that it may be single- opened. An under-frame 4 provided with a linear mobile guide groove 6 is fixed with the top of the cover along both ends at a right angle to a pivoting shaft and connected with the housing frame 1 and an opening angle regulation lever 5. The under-frame and a lower part ladder are connected with a support board 7 which is engaged with the linear mobile guide groove mounted to a housing auxiliary groove 19 for the lower part ladder 8, thereby regulating the upper part ladder 9 and the underframe so that they may float up to the position where the upper part ladder may by stacked on the lower part ladder, and what is more, they are connected with a parallel link 11 so that they may be returned with a return spring 10. The tip of a belt 13 wound up and sent with a motor 12 is spanned to a first rotator 14 and a second rotator 16 and fixed with the lower part ladder.