The present invention relates to a fixation device for a correction bar used in the operation of pectus excavatum, and more particularly, to a fixation device for securing the correction bar inserted into a thoracic cavity to a rib in an operation of correcting pectus excavatum, which a sort of thoracic malformation. The fixation device of a correction bar used in the operation of pectus excavatum includes a plurality of rib fixation units fastened to the correction bar and each having a rib support portion and a fastening portion formed at both ends thereof, the rib support portion being formed of a hook portion bent in such a manner as to be hooked and secured to a rib, and the fastening portion being formed of a rectangular through-hole or a slot; and a fastening screw unit adapted to fasten the plurality of rib fixation units hooked and secured to upper and lower ribs to the correction bar through the respective fastening portions of the plurality of rib fixation units.