Switch and method for manufacturing the same, and relay

A switch (31) and a relay (31A) in which the contacting surface of a contact is smooth are provided. A side surface of a fixed contact portion (33) and a side surface of a movable contact portion (34) face each other. The fixed contact portion (33) has an insulating layer (43) and a base layer (44) stacked on a fixed contact substrate (41), and a conductive layer (45) formed thereon by electrolytic plating, and the like. The side surface of the conductive layer (45) that faces the movable contact portion (34) becomes the fixed contact (46) (contacting surface). The movable contact portion (34) has an insulating layer (53) and a base layer (54) stacked on the movable contact substrate (51), and a movable contact (56) formed thereon by electrolytic plating and the like. The side surface of the conductive layer (55) that faces the fixed contact portion (33) becomes the movable contact (56) (contacting surface). The fixed contact (46) and the movable contact (56) are surfaces being in contact with the side surfaces of the mold portion in the step of growing the conductive layer (45) and the conductive layer (55) by the electrolytic plating, and the like.