A posture correction device for correcting deformation of the pelvis or lower chest area that is worn on the body in a manner so as to surround the outer periphery of the pelvic and lower chest areas of the body, the posture correction device being provided with a body attachment fitting for attaching in a manner so as to surround the outer periphery of the body, the fitting being provided with: a combination of one or more of four compression parts, including the innominate front-section compression part for contacting the front sides of the left and right innominates, the innominate rear-section compression part for contacting the rear sides of the left and right innominates, a chest front-section compression part for contacting the front sides of the left and right chest lower sections, and a chest rear-section compression part for contacting the rear sides of the left and right chest lower sections; and two fastening belts, the innominate front-section compression part comprising an inclined surface formed to be able to guide the innominate from the front outer side toward the rear center, the innominate rear-section compression part comprising an inclined surface formed to be able to guide the innominate from the rear outer side toward the center, the chest front-section compression part comprising an inclined surface formed to be able to guide the rib bones from the front in the direction expanding the ribs to the left and right, and the chest rear-section compression part comprising an inclined surface formed to be able to guide the rib bones so that the front sides of the rib bones expand to the left and right, each compression part independently allowing adjustment of the pressing force on the body.