A vacuum interrupter comprising: a stationary electrode; a stationary contact coupled to the stationary electrode; a movable contact movable to a position of contacting the stationary contact or a position of being separated from the stationary contact; a movable electrode coupled to the movable contact to support the movable contact, the movable electrode movable in a vertical direction together with the movable contact; a ceramic container receiving the stationary contact and the movable contact therein, the ceramic container having upper and lower portions open; a stationary electrode cover plate installed at a side of the stationary electrode and having a central through hole for allowing the stationary electrode to be inserted therethrough; a stationary electrode seal cup (10") connected to seal a gap between the ceramic container and the stationary electrode cover plate, a movable electrode cover plate installed at a side of the movable electrode, and having a central through hole having a diameter greater than an outer diameter of the movable electrode to allow the movable electrode to be movable in an axial direction; a movable electrode seal cup connected to seal a gap between the ceramic container and the movable electrode cover plate; a bellows having both ends connected to the movable electrode cover plate and the movable electrode, respectively, to seal a gap between the movable electrode cover plate and the movable electrode, the bellows being expandable or contractible in response to the axial movement of the movable electrode; and a central arc shielding plate fixed between the ceramic container and the stationary and movable contacts; and characterised in that the stationary electrode seal cup (10") includes a vertical portion connected to the ceramic container and a horizontal portion bent in an L-shape perpendicular to the vertical portion and connected to the stationary electrode cover plate, and wherein a protruding guide unit (10"a) protruding from the horizontal portion of the stationary electrode seal cup (10") in a perpendicular direction to the horizontal portion is provided so as to guide the central arc shielding plate to be installed in alignment in a radial direction. a stationary electrode; a stationary contact coupled to the stationary electrode; a movable contact movable to a position of contacting the stationary contact or a position of being separated from the stationary contact; a movable electrode coupled to the movable contact to support the movable contact, the movable electrode movable in a vertical direction together with the movable contact; a ceramic container receiving the stationary contact and the movable contact therein, the ceramic container having upper and lower portions open; a stationary electrode cover plate installed at a side of the stationary electrode and having a central through hole for allowing the stationary electrode to be inserted therethrough; a stationary electrode seal cup (10") connected to seal a gap between the ceramic container and the stationary electrode cover plate, a movable electrode cover plate installed at a side of the movable electrode, and having a central through hole having a diameter greater than an outer diameter of the movable electrode to allow the movable electrode to be movable in an axial direction; a movable electrode seal cup connected to seal a gap between the ceramic container and the movable electrode cover plate; a bellows having both ends connected to the movable electrode cover plate and the movable electrode, respectively, to seal a gap between the movable electrode cover plate and the movable electrode, the bellows being expandable or contractible in response to the axial movement of the movable electrode; and a central arc shielding plate fixed between the ceramic container and the stationary and movable contacts; and characterised in that the stationary electrode seal cup (10") includes a vertical portion connected to the ceramic container and a horizontal portion bent in an L-shape perpendicular to the vertical portion and connected to the stationary electrode cover plate, and wherein a protruding guide unit (10"a) protruding from the horizontal portion of the stationary electrode seal cup (10") in a perpendicular direction to the horizontal portion is provided so as to guide the central arc shielding plate to be installed in alignment in a radial direction.