A jig in a plate form capable of efficient formation of side electrodes on electronic components in a plate form. After electrode formation on one side of each electronic component, an electrode can be formed on the other side without causing spalling or chipping of the already formed side electrode. The jig 1 includes a core member 3 having a soft member 4 joined thereto and has a multiple of grooves 5 and 6 formed on reverse sides, respectively, in such a way that aligned electronic components A can be pushed into the grooves. The inner sides of each groove are composed of the soft member 4. Side electrodes B are formed on both sides of an electronic component as it is held between the opposed inner sides of grooves 5 or 6. The grooves 6 on the reverse side of the jig 1 into which the first formed side electrodes B are to be fitted may be sized to be wider than the grooves 5 on the reverse side so that electronic components A can be pushed into and pulled out of the grooves 6 without causing spalling and chipping of the already formed side electrodes B.