A cutting blade replacement jig for replacing a cutting blade of a utility unit, the cutting blade being attached to a peripheral edge part of a disk by a first fastening member and a second fastening member fastened to the first fastening member, the first fastening member passing through a disk through hole formed in the peripheral edge part and a cutting blade through hole formed in the cutting blade. The cutting blade replacement jig includes: a fastening member holder configured to hold the second fastening member； and a cutting blade holder configured to hold the cutting blade on the second fasting member held in the fastening member holder in a state where a center line of the cutting blade through hole and a center line of the second fasting member are aligned.
