The European Solar Telescope is a project for a 4-meter class telescope to be located in the Canary Islands. EST is promoted by the European Association for Solar Telescopes (EAST). This is a consortium formed by a number of research organizations from fifteen European countries (Austria, Croatia, Czech Republic, France, Germany, Hungary, Italy, the Netherlands, Norway, Poland, Slovak Republic, Spain, Sweden, Switzerland, and United Kingdom). EST will specialize in high spatial and temporal resolution using diverse instruments that can efficiently produce two-dimensional spectropolarimetric information of the thermal, dynamic and magnetic properties of the plasma over many scale heights in the solar atmosphere. In this contribution, the status of the development of the Design Study of EST is presented, emphasizing the most important aspects of the optical design, mechanical structure, AO and MCAO systems for wavefront correction, instruments and polarization analysis.