To provide a carrier driving mechanism capable of reducing the size of a sealing apparatus for a semiconductor device by making a transfer distance of a carrier longer with a fixed transfer distance of a driving mechanism, con versely speaking, if the transfer distance of the carrier is fixed, by shortening the driving distance of the driving mechanism.

In corners of a virtual square on a base plate, two metal molds 4A and 4B which make a pair are disposed. A predetermined position between the metal molds 4A and 4B is set at a stand-by position. A carrier 15A is disposed between the metal molds 4A and 4B so that it can reciprocate between the metal molds. Near both edge parts of the carrier 15A which are opposite to the metal molds 4A and 4B, respectively, guide sections 18a and 18b are disposed. A swing lever 16 has its one end selectively and slidably connected to either of the pair of guide sections 18a and 18b, with the other end hinged to a fixed frame. A driving means connected to the middle of the swing lever 16 is driven to make the middle of the swing lever 16 reciprocate along the reciprocating direction of the carrier 15A, to swing the swing lever 16.