The present invention provides a cutting machine, comprising: a worktable including an opening and an upper surface for supporting a workpiece; a supporting unit for supporting the worktable; a cutting mechanism mounted on a lower surface of the worktable and contained within the supporting unit comprising: a motor for outputting a rotation motion; a reciprocating rod driving a saw blade moving reciprocately through the opening; a motion conversion mechanism converting the rotation motion of the motor into a reciprocating motion of the reciprocating rod; and a saw blade clamp for clamping and releasing the saw blade; the saw blade clamp comprises an operating element which is disposed on the external surface of the worktable or the supporting unit. The present invention fixes the operating element on the worktable or the supporting unit, which brings operation of the saw blade clamp to a convenience position for operator, and the process of replacing the saw blade is very easy.