PURPOSE: To reduce the number of parts and improve assembling workability by providing a support plate of which hole edges at the upper and lower end side facing interval keeping parts of each pair of holes act for plate spring pressing parts where plate springs contact.
CONSTITUTION: Contacts 15, 15 facing each other are engaged with hole edges 14a, 14a of a support plate 12 by steps 15a, 15a to be positioned for the front and rear to the support plate 12. Plate springs 16, 16 facing each other for each line with the contacts 15, 15 facing each other between them are engaged with hole edges 14b, 14b of the support plate 12 substantially at the center of the plate springs 16, 16. The contacts 15, 15 facing each other are pressed to produce vertical holding action at their respective front and rear positions. The plate springs 16, 16 are provided with bent parts 16c, 16c at both ends on the breaker side and the pullout device side to position the contacts 15, 15 for the front and rear having the contacts 15, 15 between the bent parts 16c, 16c. The number of parts can thus be reduced, and the assembling workability is improved.