To provide a reclining mattress device allowing a user to stably use the device without falling backward if the user leans on the device.

The reclining mattress device comprises a first bottom frame 1, a second bottom frame 2 connected to the first bottom frame with a hinge mechanism 4 to be turnable and held at a prescribed turning angle, a spring unit 7 mounted on the upper surfaces of the first bottom frame and the second bottom frame 2, an exterior body 15 covering the spring unit, and a pair of holding members 21, longer than the first bottom frame, and separately fixed to the bottom of the first bottom frame with a prescribed space in the width direction.