An electric drive device has a motor housing accommodating an electric motor, a heat radiation base body fixed to an end surface, which is opposite side to an output shaft portion of a motor rotation shaft, of the motor housing and extending in a rotation shaft direction that is opposite side to output shaft portion, one electronic control unit of redundant system, arranged along direction in which heat radiation base body extends and having board, fixed to the heat radiation base body with thermal conduction to heat the radiation base body allowed, and the other electronic control unit of redundant system, arranged along direction in which the heat radiation base body extends and having a board, fixed to the heat radiation base body with thermal conduction to heat radiation base body allowed. Boards of both electronic control units are fixed to the heat radiation base body with boards slanting with respect to an extension direction of the heat radiation base body.