An opening and closing apparatus comprising: a lower unit case; an upper unit case disposed above the lower unit case and configured to open and close with respect to the lower unit case; a hinge configured to connect the upper unit case to the lower unit case such that the upper unit case pivots with respect to the lower unit case; characterized by a lower guide member (6; 31) disposed in the lower unit case and extending from a base end side toward a distal end side of the lower unit case; by an upper guide member (7; 32) disposed in the upper unit case and extending from a base end side toward a distal end side of the upper unit case; and by an opening/closing linking unit (10; 30) comprising a first rotating member (12; 36), a second rotating member (13; 35) and a linking portion (11; 30), the linking portion (11; 30) being configured to link the first rotating member (12; 36) and the second rotating member (13; 35), wherein as the upper unit case is opened with respect to the lower unit case, the opening/closing linking unit (10; 30) moves from the distal end side toward the base end side with the first rotating member (12; 36) moving along the upper guide member (7; 32) by being rolled and with the second rotating member (13; 35) moving along the lower guide member (6; 31) by being rolled, and as the upper unit case is closed with respect to the lower unit case, the opening/closing linking unit (10; 30) moves from the base end side toward the distal end side with the first rotating member (12; 36) moving along the upper guide member (7; 32) by being rolled and with the second rotating member (13; 35) moving along the lower guide member (6; 31) by being rolled, and wherein, when the pressing force is not applied, a posture of the upper unit case in opening and closing is maintained by a load or by a contact friction force that acts on the opening/closing linking unit (10; 30) in a direction toward the hinge. a lower unit case; an upper unit case disposed above the lower unit case and configured to open and close with respect to the lower unit case; a hinge configured to connect the upper unit case to the lower unit case such that the upper unit case pivots with respect to the lower unit case; characterized by a lower guide member (6; 31) disposed in the lower unit case and extending from a base end side toward a distal end side of the lower unit case; by an upper guide member (7; 32) disposed in the upper unit case and extending from a base end side toward a distal end side of the upper unit case; and by an opening/closing linking unit (10; 30) comprising a first rotating member (12; 36), a second rotating member (13; 35) and a linking portion (11; 30), the linking portion (11; 30) being configured to link the first rotating member (12; 36) and the second rotating member (13; 35), wherein as the upper unit case is opened with respect to the lower unit case, the opening/closing linking unit (10; 30) moves from the distal end side toward the base end side with the first rotating member (12; 36) moving along the upper guide member (7; 32) by being rolled and with the second rotating member (13; 35) moving along the lower guide member (6; 31) by being rolled, and as the upper unit case is closed with respect to the lower unit case, the opening/closing linking unit (10; 30) moves from the base end side toward the distal end side with the first rotating member (12; 36) moving along the upper guide member (7; 32) by being rolled and with the second rotating member (13; 35) moving along the lower guide member (6; 31) by being rolled, and wherein, when the pressing force is not applied, a posture of the upper unit case in opening and closing is maintained by a load or by a contact friction force that acts on the opening/closing linking unit (10; 30) in a direction toward the hinge.