The present invention aims to provide a steering control device capable of restraining the occurrence of the situation of unintentionally regeneratively controlling a synchronous electric motor, even when applying guard processing to an estimate variation being a rotation amount of the synchronous electric motor calculated based on induced voltage. An update amount calculation processing part M54 operates a control angle theta c by an update amount delta theta c for controlling steering torque Trqs in target torque Trqs* by making a feedback process. In this case, the update amount calculation processing part M54 applies guard processing to the update amount delta theta c on the basis of an estimate variation delta theta c2 being a speed corresponding value based on estimation of an induced voltage observer M46. Here, when a command current set by a command current setting processing part M24 is zero, the update amount calculation processing part M54 sets a value of applying the guard processing to the estimate variation delta theta c2 as the update amount delta theta c. When the command current is zero and the update amount delta theta c is fixed to a guard value, an electric passage of the synchronous electric motor and a battery is cut off.