An engine having a low pressure EGR system includes: an intake line suctioning outdoor air and transferring the outdoor air to a combustion chamber; a turbocharger actuated by exhaust gas which flows in an exhaust line to compress gas which flows in the intake line; a supercharger installed at a downstream side of the turbocharger; a low pressure EGR line branched at one side of the exhaust line and joined to an upstream side of the turbocharger to recirculate the exhaust gas; a recirculation line branched on the intake line at a downstream side of the supercharger and joined to the intake line at an upstream side of a point where the low EGR line and the intake line meet; and a control unit controlling the actuation of the supercharger. The control unit actuates the supercharger in the case of a coasting driving condition.