An in-lane drive assist device comprising: a steering unit that is steered by a driver; a turning unit for turning a turning wheel (5FL, 5FR) that is mechanically detached from the steering unit; a lane deviation determination means for determining a presence/absence of lane deviation with respect to a traveling lane; a drive assist turning amount calculation means for calculating a drive assist turning amount for generating a yaw moment in a direction to return a vehicle into the lane, when a lane deviation is determined to be present; a turn control means for controlling a turning amount of a turning unit based on a steering amount of the steering unit when a lane deviation is determined to be absent, and controlling the turning amount based on a drive assist turning amount when a lane deviation is determined to be present; and a self-aligning torque inferring means for inferring the self-aligning torque based on the steering amount; a target steering reaction force calculation means that calculates a target steering reaction force based on a steering reaction force characteristic that is set so that the self-aligning torque increases as the steering reaction force increases; a steering reaction force control means for controlling the steering reaction force based on the target steering reaction force; a lateral position detection means for detecting a lateral position of the host vehicle with respect to a white line; and an offset means for offsetting the steering reaction force characteristic more in a direction in which an absolute value of the steering reaction force is increased as the lateral position becomes closer to the white line, wherein the offset means maintains an offset amount of immediately before the determination, when a lane deviation is determined to be present. a steering unit that is steered by a driver; a turning unit for turning a turning wheel (5FL, 5FR) that is mechanically detached from the steering unit; a lane deviation determination means for determining a presence/absence of lane deviation with respect to a traveling lane; a drive assist turning amount calculation means for calculating a drive assist turning amount for generating a yaw moment in a direction to return a vehicle into the lane, when a lane deviation is determined to be present; a turn control means for controlling a turning amount of a turning unit based on a steering amount of the steering unit when a lane deviation is determined to be absent, and controlling the turning amount based on a drive assist turning amount when a lane deviation is determined to be present; and a self-aligning torque inferring means for inferring the self-aligning torque based on the steering amount; a target steering reaction force calculation means that calculates a target steering reaction force based on a steering reaction force characteristic that is set so that the self-aligning torque increases as the steering reaction force increases; a steering reaction force control means for controlling the steering reaction force based on the target steering reaction force; a lateral position detection means for detecting a lateral position of the host vehicle with respect to a white line; and an offset means for offsetting the steering reaction force characteristic more in a direction in which an absolute value of the steering reaction force is increased as the lateral position becomes closer to the white line, wherein the offset means maintains an offset amount of immediately before the determination, when a lane deviation is determined to be present.