To provide a device of a simple structure for preventing futon from slipping off from a side of a bed and assisting a sick person and the aged in safely and stably getting on and off the bed by oneself.

The device (10) for a bed comprises both flat insertion parts (12 and 38) to be inserted between the upper surface (42) of a bed and a mat or futon (44) placed on the upper surface (42) of the bed (or between mats or futon laid on the bed one on top of another) and a pair of column parts (14, 16, and 20) of which the lower ends are supported by the insertion parts (12 and 38) and which are arranged at an interval along a side edge of the bed and extended upward up to their upper ends. The distance of arrangement interval of the pair of column parts is slightly larger than a human shoulder width, and the void between the pair of the column parts is of a size to allow a person to pass.