PROBLEM TO BE SOLVED: To provide a medical bed device capable of coping with an impact of load fluctuation and achieving required mobility performance without using a load sensor.SOLUTION: A medical bed device 1 includes: a top plate 3 on which a subject is placed on the placement surface and a top plate moving part 5 having a support mechanism 15 for supporting the top plate 3 so as to move it along a longitudinal direction of the top plate 3, and a roller 17 that contacts an opposing surface facing the placement surface, and moves the top plate 3 in the longitudinal direction by the rotation around the rotational axis. The roller 17 includes a first rigid part 173 having predetermined rigidity, and a second rigid part 175 having higher rigidity than the predetermined rigidity that sandwiches the first rigid part 173 along the rotational axis. At least one of the first rigid part 173 and the second rigid part 175 has an outer diameter that contacts the opposing surface at at least one or more points in a state that the subject is not placed on the top plate 3.
