A motor-driven compressor includes a housing having at one end thereof an accommodation space, an electric motor, a motor driver circuit provided in the accommodation space and having a circuit board, a connector having a bus bar electrically connected to the circuit board, and a cylindrical portion located at the one end of the housing and extending toward the direction close to the electric motor. The housing has a mounting hole communicating with the accommodation space and the interior of the cylindrical portion. The bus bar has a bent shape having opposite ends extended toward the direction close to the electric motor. The connector is disposed in the mounting hole with one end of the bus bar inserted in the cylindrical portion and the other end of the bus bar inserted in the accommodation space. The mounting hole is closed up by a cover with a seal member provided therebetween.