To provide a door opening-closing mechanism capable of easily attaching and detaching a checker mechanism without using a screw or the like.

This door opening-closing mechanism has a female 100 having an inside space, a male 200 rotatably arranged in the inside space of the female 100, and a case assembly 300 arranged in the male 200, capable of freely rotating the male 200 to the female 100 and controlling rotational torque of holding a rotational position in a predetermined angle range. The case assembly 300 has ball plates 310 and 350 fitted to a locking piece 302 and arranging a plurality of checker balls 55 in an annular ring shape, groove plates 320 and 340 carving an annular ring-shaped groove on one surface to be fitted with the ball plates 310 and 350, and a spring 330 sandwiched between the groove plates 320 and 340 and pressing the groove plates to the ball plates via the plurality of checker balls 55.