An actuator for an electromechanical parking brake having a housing with a brush card assembly, the actuator comprising: a main housing having a motor seat and a gear seat; a motor assembly disposed in the motor seat and providing torque; a gear assembly rotated by torque from the motor assembly and performing a reduction function through a plurality of gears; and an inner housing combined with the main housing to fix the gear assembly and having an integrated brush card part electrically connected to the motor assembly, wherein the inner housing has: a main body part; the brush card part disposed at a side of the main body part and having motor terminals and a brush constituting a brush card; and a ring gear part disposed at an opposite side of the main body part corresponding to an opposite side to the brush card part, accommodating planetary gears of a planetary gear set, and having revolution gear teeth on an inner circumferential surface for revolution of the planetary gears, wherein the brush card part, the main body part and the ring gear part are extending in a direction perpendicular to a motor shaft of the motor assembly and a resultant output shaft of the planetary gear set, the actuator characterised in that: the brush card part, the main body part and the ring gear part are formed integrally in the inner housing, the motor terminals, a choke coil, and a brush are installed inside the brush card part, the motor terminals are integrally formed with the brush card part through insert injection molding, and the choke coil and the brush are assembled into the brush card part through a post process, and the choke coil is electrically connected to the motor terminals by spot welding through bonding holes formed at the upper portion of the brush card part. a main housing having a motor seat and a gear seat; a motor assembly disposed in the motor seat and providing torque; a gear assembly rotated by torque from the motor assembly and performing a reduction function through a plurality of gears; and an inner housing combined with the main housing to fix the gear assembly and having an integrated brush card part electrically connected to the motor assembly, wherein the inner housing has: a main body part; the brush card part disposed at a side of the main body part and having motor terminals and a brush constituting a brush card; and a ring gear part disposed at an opposite side of the main body part corresponding to an opposite side to the brush card part, accommodating planetary gears of a planetary gear set, and having revolution gear teeth on an inner circumferential surface for revolution of the planetary gears, a main body part; the brush card part disposed at a side of the main body part and having motor terminals and a brush constituting a brush card; and a ring gear part disposed at an opposite side of the main body part corresponding to an opposite side to the brush card part, accommodating planetary gears of a planetary gear set, and having revolution gear teeth on an inner circumferential surface for revolution of the planetary gears, wherein the brush card part, the main body part and the ring gear part are extending in a direction perpendicular to a motor shaft of the motor assembly and a resultant output shaft of the planetary gear set, the motor terminals, a choke coil, and a brush are installed inside the brush card part, the motor terminals are integrally formed with the brush card part through insert injection molding, and the choke coil and the brush are assembled into the brush card part through a post process, and the choke coil is electrically connected to the motor terminals by spot welding through bonding holes formed at the upper portion of the brush card part.