A motor-driven compressor includes a shell, an electric motor, a first conductor electrically connected to an external power source, a second conductor electrically connected to the electric motor, a connector connecting the first conductor and the second conductor and a connector case. The connector case has a first case member, a second case member, a first and a second seal members interposed between the first and the second case members, a hole through which the first conductor is inserted and a third seal member sealing between the first conductor and the connector case. A first main seal of the first seal member and a second main seal of the second seal member cooperate to form a cylindrical seal portion for sealing the second conductor that is inserted through the cylindrical seal portion when the first and the second seal members are joined.