To provide a safety bar adjusting mechanism which facilitates mounting work of a safety bar.

This safety bar 10 includes a terminal 11 being extended in the forward and backward directions of a vehicle, and a support 12 arranged on a front end side of the terminal 11 and being extended in the direction of width of the vehicle. A rear end side of the terminal 11 is fitted into a cylindrical fitting member 3 provided on a side of a seat, and is provided to turn freely around an axial line X in the forward and backward directions of the vehicle together with the fitting member 3 and move in the forward and backward directions of the vehicle for the fitting member 3 while it is fitted into the fitting member 3. The fitting member 3 has a through-hole 3a extended like long hole in the forward and backward directions of the vehicle, and a rear end side of the terminal 11 has a through-hole 11b extended in the direction crossing the axial line X in the forward and backward directions of the vehicle orthogonally. A bolt 4 for fixing the rear end side of the terminal 11 and the fitting member 3 in the forward and backward directions of the vehicle and connecting them to turn around the axial line X in the forward and backward directions of the vehicle is inserted into each through-hole, and a nut 40 is screw-fitted to a threaded section of the bolt 4.