Joining method and apparatus therefor

A nitrogen tank (22), a rotary pump (30) and a mechanical booster pump (31) are connected to a connector receptacle (12) of a connecting device (10) for performing diffusion bonding. The apparatus also includes a pressure sensor (22). In the compound container (12), a nitrogen atmosphere is prepared. The nitrogen feed rate is controlled so by controlling by means of a control circuit (38), that the pressure substantially to a range between 3 and 10 In such a state, a hydraulic cylinder (44) is brought a second electrode (16) in the vicinity of a first electrode (14) by means of a rod (46), so that finally a first object to be bonded (W1) and a second is to be connected object (W2), which are disposed on the first electrode (14) are pressed against each other. Moreover, by the first electrode (14) and the second electrode (16) applied power to the first object to be bonded (W1) and the second object to be bonded (W2).