To provide a composite semiconductor device capable of preventing malfunction of preventing electrical circuits and contributing to miniaturization of a power converter. A composite semiconductor device 10 has a structure in which a first power semiconductor element 13 that passes current from a second terminal C1 to a third terminal E1 according to a signal input from a first terminal G1 and a second power semiconductor element 16 that passes current from a second terminal C2 to a third terminal E2 according to a signal input from a first terminal G2 are formed in a single substrate (chip) 20. The third terminal E2 of the second power semiconductor element 16 is electrically connected to the first terminal G1 of the first power semiconductor element 13. A current path for transferring electric charge from the second terminal C1 of the first power semiconductor element 13 to the first terminal G2 of the second power semiconductor element 16 when the potential of the second terminal C1 of the first power semiconductor element 13 is increased with time is provided.