To provide mattress structure automatically pulling up the body in raising its back to lessen pressure applied to the abdomen, and decreasing a load to the skin due to shear force f.

This mattress structure includes: a bed body 61 provided with a back raising mechanism for switching a movable portion 62 corresponding to the upper half of the body from the horizontal state to the inclined state; and a mattress configured on the bed body 61. The mattress includes: a body side bedding 41 put in the inclined state together with the bed body; and a sliding bedding 51 superposed on the body side bedding 41 to slidably move. One end of a connecting member 53 is connected to the sliding bedding 51, and the other end of the connecting member 53 is connected to a pulling portion 63. The pulling portion 63 pulls the connecting member 53 as the movable portion 62 is inclined to enter the back raising state. The sliding bedding 51 is pulled up to the vertex side by pulling the connecting member 53.