A motor control device, comprising: a motor case (25, 225) including a motor arranged on a lower side; a housing (40, 400), which is provided to have a power supply connector mounted thereon and cover an upper portion of the motor case (25, 225); and a control unit, which is arranged on a side opposite to an output side on an output shaft of the motor in a space formed by the motor case (25, 225) and the housing (40, 400), wherein the control unit includes: a filter portion, which is arranged in an upper portion of the control unit and is connected to the power supply connector; a control board, which is arranged below the filter portion, the lower side being a side of the output shaft of the motor, the control board having mounted thereon circuit components (4, 35a, 35b) configured to supply an electric current to the motor; and a shield plate (50, 500), which is arranged between the filter portion and the control board, characterized in that the shield plate (50, 500) is grounded to the motor case (25, 225), and in that the motor control device further comprises an outer circumferential wall, which is circumferentially formed around an outer circumference of the shield plate (50, 500), the outer circumferential wall and a wall portion of the motor case (25, 225) having a clearance therebetween, the clearance having a waterproofing member arranged therein, the waterproofing member having an outer edge portion of the housing (40, 400) inserted therein. a motor case (25, 225) including a motor arranged on a lower side; a housing (40, 400), which is provided to have a power supply connector mounted thereon and cover an upper portion of the motor case (25, 225); and a control unit, which is arranged on a side opposite to an output side on an output shaft of the motor in a space formed by the motor case (25, 225) and the housing (40, 400), wherein the control unit includes: a filter portion, which is arranged in an upper portion of the control unit and is connected to the power supply connector; a control board, which is arranged below the filter portion, the lower side being a side of the output shaft of the motor, the control board having mounted thereon circuit components (4, 35a, 35b) configured to supply an electric current to the motor; and a shield plate (50, 500), which is arranged between the filter portion and the control board, a filter portion, which is arranged in an upper portion of the control unit and is connected to the power supply connector; a control board, which is arranged below the filter portion, the lower side being a side of the output shaft of the motor, the control board having mounted thereon circuit components (4, 35a, 35b) configured to supply an electric current to the motor; and a shield plate (50, 500), which is arranged between the filter portion and the control board, characterized in that the shield plate (50, 500) is grounded to the motor case (25, 225), and in that the motor control device further comprises an outer circumferential wall, which is circumferentially formed around an outer circumference of the shield plate (50, 500), the outer circumferential wall and a wall portion of the motor case (25, 225) having a clearance therebetween, the clearance having a waterproofing member arranged therein, the waterproofing member having an outer edge portion of the housing (40, 400) inserted therein.