An electric power steering device comprising: an assist mechanism that applies assist force from a motor to a steering mechanism of a vehicle; and a control unit that controls drive of the motor based on an assist command value (Ta*) associated with a target value for the assist force, wherein the control unit includes: a basic assist component calculation unit that calculates a first assist component (Ta1*) serving as a basic component for the assist force based on steering torque (Th) applied by the steering mechanism in response to steering operation of the vehicle; a compensation component calculation unit that calculates a compensation component (Ta3*) associated with a reverse input acting on the steering mechanism from steered wheels of the vehicle; and an assist command value calculation unit that calculates the assist command value (Ta*) by compensating the first assist component (Ta1*) based on the compensation component (Ta3*), wherein the compensation component calculation unit includes: a reverse input detection unit that detects or estimates the reverse input; and a filter unit (81a, 82a) that extracts a specific frequency component (Te1, Te2) belonging to a certain frequency band from the detected or estimated reverse input; characterized in that the compensation component calculation unit further includes: a phase adjustment unit (81b, 82b) that adjusts the phase of the specific frequency component (Te1, Te2) extracted by the filter unit (81a, 82a), wherein the compensation component calculation unit calculates the compensation component (Ta3*) based on the phase-adjusted specific frequency component. an assist mechanism that applies assist force from a motor to a steering mechanism of a vehicle; and a control unit that controls drive of the motor based on an assist command value (Ta*) associated with a target value for the assist force, wherein the control unit includes: a basic assist component calculation unit that calculates a first assist component (Ta1*) serving as a basic component for the assist force based on steering torque (Th) applied by the steering mechanism in response to steering operation of the vehicle; a compensation component calculation unit that calculates a compensation component (Ta3*) associated with a reverse input acting on the steering mechanism from steered wheels of the vehicle; and an assist command value calculation unit that calculates the assist command value (Ta*) by compensating the first assist component (Ta1*) based on the compensation component (Ta3*), wherein a basic assist component calculation unit that calculates a first assist component (Ta1*) serving as a basic component for the assist force based on steering torque (Th) applied by the steering mechanism in response to steering operation of the vehicle; a compensation component calculation unit that calculates a compensation component (Ta3*) associated with a reverse input acting on the steering mechanism from steered wheels of the vehicle; and an assist command value calculation unit that calculates the assist command value (Ta*) by compensating the first assist component (Ta1*) based on the compensation component (Ta3*), wherein the compensation component calculation unit includes: a reverse input detection unit that detects or estimates the reverse input; and a filter unit (81a, 82a) that extracts a specific frequency component (Te1, Te2) belonging to a certain frequency band from the detected or estimated reverse input; characterized in that a reverse input detection unit that detects or estimates the reverse input; and a filter unit (81a, 82a) that extracts a specific frequency component (Te1, Te2) belonging to a certain frequency band from the detected or estimated reverse input; characterized in that the compensation component calculation unit further includes: a phase adjustment unit (81b, 82b) that adjusts the phase of the specific frequency component (Te1, Te2) extracted by the filter unit (81a, 82a), wherein a phase adjustment unit (81b, 82b) that adjusts the phase of the specific frequency component (Te1, Te2) extracted by the filter unit (81a, 82a), wherein the compensation component calculation unit calculates the compensation component (Ta3*) based on the phase-adjusted specific frequency component.