OFFLINE TEACHING DEVICE

In an offline teaching device in the related art, in the case of changing a teaching program, even in the case of performing the same change at each teaching point, it is necessary to perform the change with respect to each teaching point. The offline teaching device of the present disclosure has a selection function, a first change function, a second change function, a welding line storage function, and a teaching program storage function. The selection function causes one welding line among a plurality of welding lines stored in the welding line storage function to be selected. The first change function causes content of a welding conditions configuring the welding line selected with the selection function to be changed. The second change function causes the welding conditions of entire instructions in the teaching program having the same welding line identification information as welding line identification information that is assigned to the welding line selected with the selection function to be changed to the same content as content changed with the first change function.