PROBLEM TO BE SOLVED: To provide a reciprocating tool in which replacement work of a blade is easier comparison to conventional tools.SOLUTION: A center shaft member 12 fixed to a housing 1 penetrates a center hole 16 provided in a blade set, and is protruded downward from a blade holder 5. A screw is formed on a tip end side outer peripheral surface of the center shaft member 12, and the blade set is installed to the housing 1 in a detachable manner by screwing a dial knob 6 with the center shaft member 12. The dial knob 6 has a ratchet part 6c, and rotation of the dial knob 6 in a loosening direction is prevented by making a loosening stopper 14b provided in the housing 1 be engaged with the ratchet part 6c.
