PURPOSE: To provide a titled welder which makes the pressurizing force between electrodes constant, and permits detection of said pressurizing force by means of a reed switch and a permanent magnet by interposing a spring between a rod which is driven by treading force and a movable arm mounted with a movable electrode.

CONSTITUTION: When the operator treads a pedal 14 and turns a foot lever 12, a rod 8 is forced upward to turn a movable arm 3 by means of a spring 10, by which a movable electrode 5 is moved downward until said electrode contacts with objects 18 to be welded. When the operator exerts additional treading force to force the rod 8 upward, the spring 10 deflects to exert pressurizing force between the electrode 5 and a stationary electrode 7; at the same time, a permanent magnet 17 fitted to an L-shaped lever 16 mounted to the rod 8 moves upward and approaches to a reed switch 15 mounted to the movable arm, and to close the contacts thereof, then the switch transmits a signal. Thus, the exertion of the required pressurizing force between the electrodes 5 and 7 is detected. Welding voltage is applied to weld the objects to be welded.