Smart entry system

A smart entry system that releases a lock of an opening/closing body, the smart entry system comprising:

• a transmission unit that transmits a call signal to a mobile key by wireless communication;
• a reception unit that receives a response signal from the mobile key responding to the call signal;
• and
• a control unit that outputs a call signal transmission command to the transmission unit, performs authentication of the response signal when the reception unit receives the response signal, and outputs a command for unlocking the opening/closing body based on a result of the authentication, wherein
• the call signal is transmitted by a polling system,
• the control unit includes an output strength setting unit that changes and sets an output strength of the call signal,
• the mobile key has a plurality of input units that perform input for unlocking or locking the opening/closing body by a pressing operation of a user,
• the mobile key is configured to output a strength change request signal when the plurality of input units are pressed in a procedure different from a primarily used pressing operation,
• when the output strength setting unit receives the strength change request signal, the output strength setting unit determines a distance between the transmission unit and the mobile key of a time of receiving the strength change request signal as a user's intended distance, and
• the output strength setting unit changes and sets the output strength of the call signal according to the user's intended distance.