An electromagnetic relay for moving, in a reciprocating manner, an actuator plate by electrically energizing an electromagnetic unit, causing a pair of neighboring first and second movable contacts (57, 58) to make and break contacts with a pair of neighboring first and second stationary contacts (31, 32) opposing the movable contacts (57, 58), said electromagnetic relay comprising a movable contact plate assembly including a pair of first and second plate portions (55, 56) extending in parallel to each other and separated by a first slit defined between the first and second plate portions (55, 56); said pair of first and second movable contacts (57, 58) mounted on the first and second plate portions (55, 56), respectively; said pair of first and second stationary contacts (31, 32) fixed to oppose to the first and second movable contacts (57, 58), respectively; a shield plate disposed in the first slit between the first movable and stationary contacts (57, 31) and the second movable and stationary contacts (58, 32), the shield plate having a first major surface adjacent to the first movable and stationary contacts (57, 31) and a second major surface adjacent to the second movable and stationary contacts (58, 32), characterised in that at least one of the first and second major surfaces includes parallel grooves so that an insulation distance between the first movable and stationary contacts (57, 31) and the second movable and stationary contacts (58, 32) is increased and particles generated by contacts of the first movable and stationary contacts (57, 31) and contacts of the second movable and stationary contacts (58, 32) are captured by the parallel grooves; and a stationary contact terminal supporting the first and second stationary contacts (31, 32), the stationary contact terminal including a second slit, wherein the shield plate is positioned in the second slit of the stationary contact terminal between the first movable and stationary contacts (57, 31) and the second movable and stationary contacts (58, 32). a movable contact plate assembly including a pair of first and second plate portions (55, 56) extending in parallel to each other and separated by a first slit defined between the first and second plate portions (55, 56); said pair of first and second movable contacts (57, 58) mounted on the first and second plate portions (55, 56), respectively; said pair of first and second stationary contacts (31, 32) fixed to oppose to the first and second movable contacts (57, 58), respectively; a shield plate disposed in the first slit between the first movable and stationary contacts (57, 31) and the second movable and stationary contacts (58, 32), the shield plate having a first major surface adjacent to the first movable and stationary contacts (57, 31) and a second major surface adjacent to the second movable and stationary contacts (58, 32), characterised in that at least one of the first and second major surfaces includes parallel grooves so that an insulation distance between the first movable and stationary contacts (57, 31) and the second movable and stationary contacts (58, 32) is increased and particles generated by contacts of the first movable and stationary contacts (57, 31) and contacts of the second movable and stationary contacts (58, 32) are captured by the parallel grooves; and a stationary contact terminal supporting the first and second stationary contacts (31, 32), the stationary contact terminal including a second slit, wherein the shield plate is positioned in the second slit of the stationary contact terminal between the first movable and stationary contacts (57, 31) and the second movable and stationary contacts (58, 32).