The present invention relates to a rehabilitation exercise device for maintaining the function of a hand and preventing deformation, and more particularly, to a rehabilitation exercise device for eliminating an out-of-water work made up of a muscle of a hand, A first finger mount 110 and a second finger mount 120 which are formed with insertion holes 110a, 120a, 130a, 140a and 150a which are inserted into and fingered with fingers to limit the bending of the inserted finger joint, A finger guide member 100 including a third finger mount 130, a fourth finger mount 140, and a fifth finger mount 150 A gap (200) formed between the finger mounts (110, 120, 130, 140, 150) while the finger guide member (100) is arranged corresponding to the arrangement of the fingers When the finger mounts 110, 120, 130, 140 and 150 including the clearance 200 are pulled in the parallel direction by the force of the fingers, elasticity of the elastic band 310 connected to the finger mounts 110, 120, An elastic band member (300) for causing the working muscle to contract Wherein the elastic band member 300 is a strip-shaped elastic band 310 having an elastic force to be tensed and contracted and has an intermediate position on the side where the finger mounts 110, 120, 130, 140 and 150 face each other, 120, 130, 140 and 150 are protruded from the hand direction position and the palm direction position with respect to the finger mounts 110, 120, 130, 140 and 150 in parallel with each other, The elastic band member 310 of the elastic band member 300 is formed so as to be positioned at a position in the hand direction of the opposite circumferential surface of the finger mounts 110, 120, 130, 140, And is connected to a stunning bone part with respect to the longitudinal direction of the finger and a wide band 310c at the stunning valley part connecting the stump part and the horse osteolysis part, To be connected to (310b), and wherein the end of osteotomy site is connected by a long and narro
