A reciprocating working machine has a lower blade and an upper blade overlapping each other. The lower and upper blades have respective elongated apertures slidably fit around lower and upper eccentric cams, respectively. The lower and upper eccentric cams are arranged at a 180-degree phase from each other. One of the upper eccentric cam and the lower blade has a beveled surface facing the other. The lower blade and the upper eccentric cam are relatively moved away from each other via the beveled surface.
